how is this type of attitude not sufficient reason to not bother hiring someone? I immediately don't want to work with or for you.
I know this. And I wouldn't want to work with JS devs. At all. It's a win-win for all of us that I don't apply to those positions.
It’s a sign of a bad attitude.
One can be blunt without displaying a trashy attitude, and it doesn’t take that much effort. Most people tell me that I am the most blunt person they know in that I will give some of the most honest observations whether they are uncomfortable or not. I also have a reputation of being one of the nicest people many people know, never needing to put down one group of people to appease another, probably one of the biggest engineering productivity killers one can create (negative politics, cliques, etc.). Engineers often will vent to me (coworkers, teammates, people from various programming communities, etc.), and I lend a sympathetic ear to all, which in turn builds trust, comraderie, and helps use my knowledge & experiences to help guide responses & resolutions to situations generating stress to a healthy outcome for all.
It shouldn’t take much effort to treat each person with respect & humanity - if it does, one should look inwards at maybe something being wrong with oneself than to other people, and work on culling out the toxic attitude.
They're just biases that haven't a good justification. I usually keep this sort of bias to myself because I recognize it for what it is. Honestly though I wouldn't apply for such positions, either, so the bias problem never surfaces.