I really have no strong feelings one way or the other about the Transformer movies, but I'll point out that the Transformers franchise already existed, Bay didn't make it. However, it's really the only example I can think of as far as franchises that were "ruined" (in someone's opinion) by someone other than the creator of the franchise (so you can't pick George Lucas). I suppose there are people who will argue Star Trek. I don't know. Anyone out there still hate the Mission Impossible films?