1. The casual racism. He has used the 'n' word on his podcasts on multiple occasions and has defended a bunch of other racist things he's said.
2. The casual misogony. He regularly attacks women who speak out against the awful things he says about women, and encourages his followers to harrass them online. It happens all the time.
3. He threatened to fire his employees that wanted to unionize (and retracted his threat when AOC tweeted at him that this was illegal) and ended a program in the company that allowed for anonymous complaints to HR.
He's a terrible person. A lot of guys go through that frat boy phase, but most grow out of it eventually. He never did, and started a company encouraging all of that crap.