When you attack someone for something of which you are guilty and a prime example it dilutes the punch doesn't it? Why do folks do it?

There are two types of hypocrite. One just thinks their sh*t smells sweeter than most. They genuinely believe that what they are criticizing is bad. They just lack the self awareness to see they are also guilty of it.

The other type are people who don't believe what they're saying. They criticize others as a weapon of social and political warfare, not because they actually believe in the moral principles they advocate, or that they are actually morally superior, or that their enemy is necessarily guilty of violating those principles. They are just throwing mud, and hoping some will stick, because they wish to influence 3rd parties. They may be recognized as a hypocrite without virtue, though what's the alternative? Nobody respects scum, so the scum has to virtue signal if they wish to be respected. They just hope nobody sees through it.