M. Night Shyamalan is known for making use of twist endings in almost all his films, and they have always been incredibly divisive; here's why. It feels a bit weird to remember now, but at one point early on, many felt Shyamalan was destined to be the next Alfred Hitchcock, the heir apparent to Hitch's throne when it came to suspense thrillers. This was primarily due to The Sixth Sense, which took the world by storm in 1999 and remains one of the best-remembered movies of that decade.
Looking back, The Sixth Sense still entirely holds up, with great performances, a striking visual style, expertly crafted scares, and main characters that are easy to relate to and empathize with. The Sixth Sense's now-famous twist, in which it's revealed that Bruce Willis' Dr. Malcolm Crowe had been dead since the film's opening scenes and only appeared to Haley Joel Osment's Cole as a ghost, also holds up, with no noticeable plot holes surrounding it. It's a remarkable bit of craftsmanship that has aged almost flawlessly.
Upon release, The Sixth Sense's bravura twist became its most talked-about aspect, but unfortunately, few have held up as well since. Perhaps Shyamalan feels pressure to measure up to his first hit twist, but he's yet to really do so, and some of his twists have been outright regrettable. The problem is that plot twists that take a hard turn are difficult to pull off without upsetting the balance of the movie. When they go too far, they can become implausible at best or completely silly at worst. This has led to the divisive reputation their use now has among fans, and the worries many had going into the release of his new movie Old. When Shyamalan does a twist well, like in The Sixth Sense or with Mr. Glass in Unbreakable, it adds greatly to his films. When he does it poorly though, the entire movie can be undercut.
The general go-to example when it comes to just how much one of M. Night Shyamalan's twist going wrong can ruin an otherwise good film is The Village, which promoted itself as a monster movie about the creatures that stalk a remote community. Up until the twist ending, many enjoyed The Village, as the cast was full of talented actors, and Shyamalan's visual style was in effect as usual. Then the twist happens, and the entire preceding story is essentially thrown away. Nothing the audience thought it knew was actually true, the monsters weren't even real, and on top of that, Shyamalan gave himself a cheeky cameo during the twist that gave off the impression he thought it was extremely clever.
The problems arguably began with Signs. While many people did enjoy it overall, it began to show the downward trend in the quality of Shyamalan's twist endings. After presenting audiences with a great blend of alien invasion and tense horror, Shyamalan reveals that Signs' aliens, who up until that point had appeared to be an existential threat to humanity, were fatally weak against water–water, of course, being the substance that covers a good three quarters of the Earth, begging the question of why the aliens risked invading a death trap. Not only do M. Night Shyamalan's sometimes silly twists hurt his better efforts, they serve to make his lesser works even less enjoyable, such as with The Happening. While it remains to be seen what the consensus view of Old's twist will be, perhaps Shyamalan should consider giving them a rest for a while.