I don't think anyone would have cared if he wasn't on twitter, which is a social media outlet for the entire world to see.
Keep your bullshit in your box, and you can smell it all you want. When your bullshit becomes overwhelmingly public, the public has every right to declare they don't like the way your shit smells.
That people are upset because "people who don't care about the show have influenced it" is ridiculous. Maybe you should be mad at the guy who opened himself up for the drama by posting a stream of vomit on twitter.
And if the goalposts are moved to say "Well, he's been this way on Twitter forever!" well, who cares? Now is the time where it backfired.
This makes no sense.
Say stupid shit on your own radio show - OK
Say stupid shit on Twitter - Take away radio show. You can still post on twitter though
???
Him just posting something on twitter is not "overwhelmingly public". Only his followers see it, and the majority of those probably miss most of his tweets scrolling through their feed. If you weren't following him you'd never have seen his rant. It only became truly public when blogs picked up on it and made it a big deal on a slow news day.