@tsarstepan,
I don't know if they ruined any actors' careers, but I thought the storylines of Grey's Anatomy, Desperate Housewives, and Lost went completely off the rails. Once that happened, I had no respect or faith in the writers so stopped watching. It was a shame because I thought they all started out so well. Pretty much after that I focussed mainly on Cdn and UK shows, and haven't watched another US series.