My UO for showrunners, writers (TV, movies, books, plays, etc.), and fans is just because someone (or lots of someones) guessed where your mystery was going does not automatically make the journey to get there boring or bad. There still can be a lot of intrigue, interest, plot between A to Z if creativity is there.
This is in reference to Lost and GoT (two of my favorite shows that caused lots of disappointment). But I think many people (including fans) can mess a story up by wanting it to constantly push the enevelope, shock, mind bend etc. I like that too when it is done well but I like a good, plausible, and a "not total character changing for no reason story" done well too and sometimes better.