From my comment: "I wouldn't hire me to work on a JavaScript stack.... They're just biases that haven't a good justification."

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.

I wouldn't want to work with you on anything, as I strongly suspect your attitude extends well beyond javascript.

You think having preferences, and being aware of them, and avoiding environments not in line with them, makes him a bad prospective co-worker?

Having preferences is one thing, but being judgmental/presumptuous towards people working in that realm & using slang with a clear derogatory bent to describe them for something that does not inherently relate to morals is another.

It’s a sign of a bad attitude.

It's a sign of a very healthy attitude to be open about your opinions and not trying to be "nice" all the time. This is a very american thing, to be constantly positive and nice when you really shouldn't, and in my experience, it's a very detrimental thing to morale and productivity because of how obviously fake it is.

What you are saying is very different than the person’s comments I was referring to.

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.