Surprisingly, I can't think of anything. The only time I've lost interest in a game I've been following is Tokyo Mirage Sedsions: #FE, and that's for a number of reasons, including stuff like betrayal of at least one of the two core franchises in the crossover, and the very direction that the thing took. Both elements are very much specific to this game only, so I don't think I can make a generalization based on that.