Turning into a big green brute who causes untold damage to everything and everyone would be enough to traumatize most people - but Bruce Banner has even more reason to hate his transformation into Hulk. While fans may think they understand Bruce's hatred for his other self, it took a deep dive into his consciousness to expose the truth.
Hulk made his debut 60 years ago, after Bruce Banner, an unassuming scientist who abhors confrontation, suffered a nuclear accident that made him the host of human anger personified in The Incredible Hulk #1 by Stan Lee and Jack Kirby. Marvel describes Hulk as an extension of Bruce's rage, and has suggested the former Avenger is an aspect of Bruce that developed during his abusive childhood. Being anchored to such a central and destructive human emotion as anger has made Bruce Banner a ticking time bomb and seriously hampered his ability to form lasting attachments for fear of exposing them to grave danger.
Part of the reason that Bruce hates violence is because of his father Brian Banner’s reliance on it. The elder Banner’s alcoholism, neglect, and abuse eventually escalated to the point where he murdered Bruce’s mother Rebecca in front of him. After his incarceration for the crime, Brian’s anger threatened Bruce once more, causing his son to kill him in an act of self-defense. Growing up in a home that was ruled by such a tyrant, and effectively losing both parents to his father’s anger, understandably caused Bruce to disavow strong displays of emotion. However, The Incredible Hulk #460 by Peter David, Adam Kubert, and Mark Farmer points out that the arrival of Hulk gave Bruce a new reason to fear his own inner turmoil.
In this issue, Bruce Banner is finally able to articulate how being Hulk has made him afraid to feel, in much the same way that his father’s explosive personality did. He and his mother were forced to walk on eggshells to avoid setting off Brian’s outbursts. It is a huge cathartic moment for Hulk’s alter ego when Bruce confronts his dad’s shade as part of a near-death experience in this issue, showing acute awareness of his longstanding emotional damage and how the Bruce/Hulk dynamic is essential to both's survival. He admits, “I hate you because you terrorized my mother... and me... because you made me afraid to love... to hate... you made me afraid of everything!”
For a man who grew up with an abusive and neglectful father, and who is desperately trying to break the family cycle of violence, being trapped in a state where he cannot dare allow himself to feel powerful emotions is heartbreaking. Bruce’s hatred of Hulk extends beyond mere self-loathing (though many stories have made it clear that's also in the mix), as the beast within is a physical manifestation of what life used to be like in his childhood home.
This is more than just a curse spawned from a nuclear accident; it is a parting legacy from Brian Banner, one of Marvel's worst parents. Marvel has made it clear in the past that Hulk is a true part of Bruce, deserving of respect and love just as much as his human form. However, with this deeper meaning in mind, Bruce Banner's loathing of Hulk takes on a whole new meaning, as their animosity is the continuation of a harmful relationship that existed long before the gamma bomb and the Green Goliath's birth.