I'm not sure it "came out of nowhere" - Worf and Troi had been getting progressively closer ever since season 5 in episodes like "New Ground", "Ethics" (remember he made her promise to look after Alexander if anything happened to him), "A Fistful of Datas" etc.
Did I like it? I was OK with it. It's also realistic that sometimes friends hook up and then decide it doesn't really "feel right". It was nice to FINALLY get some character progression on TNG to be honest.