There are very few people that everybody likes. One of them just died.
Everybody liked Mr. Rogers. Admittedly, I have seen articles by folks who didn't like him, usually because he wasn't Fundie or Marxist enough. If somebody's only critics are frothing loons, that says a lot of good about them.
I don't have kids, and I'm way too old to have watched Mr. Rogers myself (Captain Kangaroo for me, when I saw any TV at all). But the one thing that impressed me about Mr. Rogers was how incredibly calm he was. Everything was in that same calm, quiet voice, just talking about things the way they are. Nothing seemed to ruffle his feathers. Kids need an area of calm. Their normal world is full of adults rushing around, worrying about things that kids can't understand. Mr. Rogers brought a little bit of calm. Also, he brought in new things, new ideas, and new people, all with that same calm "isn't this interesting!" attitude.