I think that people with young kids can tolerate some shows more than people who have older kids or no kids. I used to watch Barney with my niece because it was her favorite and it was fun to watch her get enthused for a show, but I couldn't stand to watch it by myself or with kids who aren't close to me.
I used to watch it with my kids. As far as a kids show goes, I had no issue with it, but Barney's voice and the signing voices were utterly annoying. And for God's sake, almost without fail, whenever I brush my teeth, I still sing the 'never let the water run' song in my head. Or even if someone runs a faucet for too long.