one of the things I find most annoying in television, is when the writers of a show clearly have no long-term ideas for where the plot is headed. As a result, story lines get started, then abandoned, and bizarre occurrences start happening with more frequency, like characters getting killed and coming back to life all the time, alternate universes where the good guys are bad and vice versa, the reappearance of a long lost twin sibling nobody knew about
-all clear indications that the writing team is just pulling sh*t out of their a$$es. You see it happen all the time, but mostly with shows that have been on the air for a long time.