Something pathetic inspires pity and contempt. If your backhand is pathetic, you probably shouldn't try out for the tennis team.
These days, when you see the word pathetic, it's pretty clear that it's no compliment. This is an insulting word for things that are so bad they bum you out. A sports team losing ten games in a row is pathetic. Someone who constantly lies, even though the lies are obvious, is pathetic. Trying to dunk a basketball and missing by three feet is pathetic. When something is astoundingly lame or awful, people love to say, "Wow. How pathetic."