I don’t really like the idea. I have had a lot of pleasant surprises from people I thought were just rude on here, not responsive, etc. Most of the time people who you think are being closed off have a lot to contribute on certain issues, or were having a particularly bad day…etc.
There is so much misinterpretation and assumed tone on the internet because of the medium. Efficient wording can appear brusk. Words when stated with different tones can have completely different and immediately clear connotations (even denotations), while when typed they can be taken any way. And something stated in a completely innocent manner can be interpreted by someone as insulting because that reader has been frustrated by posts throughout a thread, and the person just appears to be “attacking” you as well. Often, you (I include me) respond in a directly insulting manner, and the other person then rightly feels attacked, and the situation simply escalates.
And although I have argued we shouldn’t expect the worst, a straight up block will almost certainly inspire retaliations of sorts, and may be used more liberally than intended. It will reduce, if not destroy, the utility of an open Q&A site.
I know the frustration of seeing crazy responses (as I interpreted them) derail a thread. I’m sure I’ve done it. I think the best option is to consolidate responses you get, look at some sibling questions, and try re-asking in a different way, including what has been covered.