A focus on extremely high output that means poor-quality work and poor working environment.
Extreme unprofessionalism that works okay when you're a handful of guys who are close friends and all personally invested in the mission, but not when you're a big company with communication problems across the various working groups. This is normal growing pains when a company moves from "nimble start-up" into "big production", but Linus has been handling it really badly, and seems like a big part of the problem. Stepping back from the CEO role was a good first step but he's obviously still de-facto running the company.

I can't call Linus a poser since he and his team quite apparently know a massive amount about PC hardware, but the above factors mean they're going to make near-constant screw-ups, and now they're seeing real comeuppance from that.

edit: I just read the rest of the allegations on Xitter and holy shit this is worse than I thought. She really buried the lede. It's still "unprofessionalism" but a level of unprofessionalism that totally crosses the line far beyond normal growing pains. Flubbing workplace sexual harassment is a serious leadership fuckup.