Only a few things remain constant in this ever-changing universe. Death, decay, gravity, time, and there's also the fact that the Hulk will always smash. That's a universal constant and law. When you see something big and green on the screen, expect to see battered enemy bodies and more debris than you can imagine. That in itself is a problem if you're not Hulk.
Because of the green rage monsters tendency to destroy everything with reckless abandon, he's pretty much an indiscriminate walking catastrophe, especially in the Marvel Cinematic Universe. He might show an ounce of benevolence for some of his violent actions, but most of the time, Hulk is rather shameless about it. Need more proof? Here are 10 of the most shameless things he did in the MCU.
ATTACKED BLACK WIDOW
We've seen Hulk many times before in the 2000s (he's had two movies already), but his first appearance in The Avengers back in 2012 is still breathtaking, partly because Black Widow got the brunt of it. The Hulk, upon transforming due to stress and a perceived threat, suddenly starts chasing and attacking anything that moves... or is stationary.
It just so happens that even Black Widow isn't exempted from this. She might have been the peak of human physical potential, but Black Widow is a delicate ant compared to the Hulk. Even so, Hulk obviously had the intent to kill and harm her-- he succeeded on the latter. If not for Thor's intervention, Black Widow could have died earlier in the franchise.
DESTROYED PROPERTY
If Hulk only put his expertise to positive use, he would have made the demolition industry go bankrupt. The angry guy could easily flatten a high-rise building in a matter of minutes and probably even create a sinkhole to hide all the trash. Sadly, Hulk doesn't do this productively or charitably. Destroying buildings is a mere result of his collateral damage when fighting his enemies or pretty much any other action.
Hulk has certainly shown that he's capable of tearing down the whole SHIELD Helicarrier in a matter of seconds. No government, private, or personal property is safe when the Hulk is around. Sure, people might be thankful that he saved a city, but usually, that city is pretty much uninhabitable afterward.
GRUDGE AGAINST THOR
Even after one-upping Thor with that sucker-punch in the first movie, it seems Hulk's insecurities to the Asgardian never let up and went with him to Sakaar. That's why when the two of them met again on the planet in Thor: Ragnarok, things got a little too out of hand. Thor was expecting a friendly welcome, but the Hulk was somewhere else entirely.
He simply didn't want to be friendly with his old teammate and proceeded to fight him despite the lack of violent intent from Thor. It pretty much paints Hulk as a bad and lousy friend who puts his emotions and grudges first before friendship. It's not like the grudge was that bad anyway, Hulk just wants to show he's stronger.
Injured Civilians
In addition to property collateral damage, Hulk has also harmed countless of innocents. While he does actively avoid non-combatants during his skirmishes or fights, no playground is too big for the rage monster. That means innocent humans will usually get in the way of the fighting.
The MCU hasn't any of them dying to Hulk's transgressions and carelessness, but it's safe to assume that they incurred numerous physical injuries. Then, there's also the mental trauma that they might face upon getting nearly turned into a paste by a brute. There's no doubt some of these casualties won't like the color green anymore after an encounter with Hulk.
SUCKER-PUNCHED THOR
One of the most memorable moments in 2012's Avengers (apart from the entire movie) is when Thor and Hulk duked it out in the hangar of the SHIELD Helicarrier. The fight was inconclusive, and the two of them had to make it up to defeat a common and more dangerous foe.
However, Hulk doesn't seem to handle this uneasy truce as maturely as Thor. That's why he managed to slip in a sneaky and brazen sucker punch right at the Thunder God's jaw during their brief downtime after taking down a Chitauri Leviathan. Perhaps he intended it to be a bro-fist? Either way, it caught Thor off-guard.
SUPERIORITY COMPLEX
In addition to boasting the unfair win in the Sakaar arena, Hulk also let rip some hurtful words to Thor. The two of them went on a heated debate where Thor was angry and sad due to losing his father and his hammer. Apart from doing little to comfort his sad friend, Hulk also threw some dangerous weapons at Thor.
They did sort their anger out but it was clear that Hulk still thinks of himself as the more superior Avenger to Thor, often calling him "tiny Avenger" or comparing himself to a raging fire while regarding Thor as a smoldering fire. This lack of maturity from Hulk is not as bad as it sounds, of course.
ATTACKING SURTUR
Thor: Ragnarok, despite being a hilarious and lighthearted movie, ended in a rather grim way. Asgard was destroyed, and the Asgardians became refugees. Of course, that was the only way for their world-- to let Surtur destroy it so Hela can also be defeated. During that process, however, Hulk came blundering about and nearly ruined the plan.
Since Hulk is functionally immortal and his strength is proportionate to his rage, the two could have easily fought forever in a stalemate, effectively letting Hela go after the Asgardians. Thankfully, Hulk listened to reason at least for once and stopped smashing.
REFUSAL TO HELP AGAINST THANOS
It wasn't until Avengers: Infinity War that Hulk met his match or someone who could put him in place physically. That being is Thanos, and he easily defeated the combined forces of Thor, Loki, and Heimdall. Hulk, for some reason, showed up late but still got his rear handed to him in a flash by the Mad Titan.
This was the first real embarrassing defeat for the immature and childlike rage monster-- something that he'll never come to terms with. That's probably why he just sulked around inside Bruce Banner and refused to help at such a dire time in the Infinity War. Thankfully, Banner knew how to improvise, but that was rather inconsiderate of Hulk.
THOUGHT HE DEFEATED THOR FAIRLY
The rematch between Thor and Hulk in the Sakaar arena was rather inconclusive as well since Thor obviously was at a disadvantage due to his lacking Mjolnir and the paralysis disc on his neck. The Hulk, being the Grandmaster's prized gladiator didn't want Hulk to lose, so he made Thor lose.
It's not clear whether the Hulk is aware of this or not, but the former Avenger still took pride in defeating Thor. He likely thought that their fight was fair and square, even if the results were manipulated. In any case, the Hulk was rather boastful about his perceived victory, and it served to boost his ego even if deep down, he probably knew Thor was at a disadvantage.
"TIME TRAVEL!"
Even when Bruce Banner successfully reconciled his body with Hulk's in Avengers: Endgame as Professor Hulk, you could still see some traces of shamelessness in him. This was rather apparent in the scene where they used Ant-Man/Scott Lang as a guinea pig for time travel. Banner did make it clear that it was not his field but still tried and easily could have erased Scott Lang from existence.
He even passed off the failed attempt as a passable effort where the scene even became a meme. It could be that Professor Hulk was just merely being optimistic, but our money's on residual carelessness from being Hulk for too long.