8. "It's Not What I Expected"
Expectations are always a dangerous way to leave yourself disappointed, especially if you're expecting an upcoming game to be one very specific thing, but the end result turns out somewhat different.
There are certainly instances where a game flatly fails to deliver what was promised - looking at you, Anthem - but this criticism is directed more towards games that simply pivoted into a different style or type of game than fans precisely expected.
Take Resident Evil 4, which while widely regarded as one of the finest survival horror games ever made, still released to a chorus of hate from some "purist" fans who felt that, because it deviated from the series' traditional formula, it was immediately worthless.
It's this sort of attitude which will so often prompt publishers to follow trends and be content with their developers basically just releasing the same old thing every damn time.
Nobody's saying you have no right to be mad if Grand Theft Auto VI turns out to be a chess simulator, but creative leaps should be encouraged where appropriate. Otherwise, we're basically being resold the same stagnant gameplay systems and story tropes without sufficient variation.