Exactly. I wouldn't expect - nor would I want - a friend to agree with everything I said or did because it simply wouldn't make sense: I'm not perfect and neither is anyone else.
We are all different, and sooner or later friends will disagree. But some take it a step further, if you don't agree or do something they don't like, then the friendship is over. Sad.
That is surely true, for many of us. There are also times when disagreeing on certain opinions one feels very passionate about, definitely put enough of a strain on a friendship that it ceases to exist.