My sexual orientation.

[king1]

I'm not sure that, in a society where we value freedom of speech and (mostly) inclusivity, that one should have to hide a part of their life just to appease or avoid the outrage of a bunch of keyboard warriors.

It says far more about the idiots banging away on their keyboards than it does about him...  Some folks just need to take a chill pill

And yet, rather ironically  I am perhaps one of the few keyboard warriors here who has a position of declared non interest in an individuals sexuality. 
My only gripe is that many expect that I must recognise them upon their disclosure of it.

I sense a contradiction in that statement - your gripe itself almost certainly implies a declared interest.  

What exactly is the problem with recognising the disclosure anyway? you can choose not too if you insist but you seem to be avoiding the logical choice one might make in your position of simply not giving a fuck one way or the other.  You could simply choose to ignore it and move on...  Don't think it's worth losing any sleep over, just because someone we don't know personally decides to out themselves.