I'll just give you a summary:

1. Dude made a joke, in China during the opening of the tournament, complaining about porn and wanting to get around the government firewall. On essentially a public broadcast at one of the largest venues in China.
2. Dude was told to cool it because the above action is not a good idea when you're the public representative of the company and acting as the host for the entire event.
3. Dude then makes a joke obliquely referencing homosexuality. Again, this is still in China on what is still effectively a public broadcast at one of the most prominent venues there.
4. Dude gets fired, yells about it on public forum.
5. Gabe makes a rather unprofessional but not wholly unjustified response regarding the matter on the dota2 subreddit. Gabe's openness with the community is a two-edged sword, with him being surprisingly reachable despite being a multi-billionaire but that attitude also serves to make him rather unrestricted in public.

Shitstorm ensues as a bunch of non-Chinese ignoramuses defend Dude and decry Gabe without understanding anything about the social context of the situation. To wit, Dude was making Valve look really, really, really, really fucking bad to the Chinese public and even worse, mocking the fucking government while in China. As Valve's public officer. As the tournament host.

CNN doesn't send a correspondent to Saudi Arabia without telling them a few ground rules about respecting appropriate public topics, actions, and behaviors, right? Same fucking idea. Dude got several warnings before being punted out. And then he announced he was punted out while making Valve look like the bad guys when they weren't.