Getting a post or tweet picked up by a large community who doesn't see your stuff regularly can be a lot more stressful than speaking directly to your audience (in this case, direct Twitter followers) who have a lot more context on your work.
I never understood why it's such a big deal. When people guess wrong about my gender, ethnicity, preferred spoken language, etc, I correct them.
I guess if they were to argue with me about the correction and insist their guess was right, that would get old fast and I'd be as frustrated as foone.
If you're not with us, you're with them.