Can I get a small summary of why he was shitty? Never heard of this guy.
He was the most influential conservative talk show radio host...probably ever, and he is directly responsible for the shit-tier opinion based "news" programs that actively poison the minds of tens of millions of Americans each and every single day. Most, if not all, problems that you might have with opinion based "news" programs and/or conservative talk radio programming are because of this guy.
No Rush? No Tucker.
No Rush? No Hannity.
No Rush? No Ingraham.
To name the current examples of problematic programming. Basically, Fox News.
He was racist, sexist, homophobic, actively claimed that smoking does not kill you (ironic, I know), and is directly responsible for Donald Trump's presidency.
Without Rush I don't think you have President Trump in 2016, and certainly not his continued support by his base throughout the last 4+ years.
He was propaganda to the fullest extent.