There is that and in plenty of cases justified but plenty can be taken completely out of context (such as a joke).
Those who do the searches/get in a lather over this have never written anything on social media that is insulting or belittles people. I'm sure every single one is whiter than white.
Likewise, this raking over old ground from many years before, especially if young at the time, doesn't allow for people learning or changing their view.
There has to be a balance that has to be found or skilled/capable people won't put themselves forward for important roles in things like Politics.