I got burned with an attitude like this: unexpectedly, people who had downloaded my open source tool for free started expecting support. Some of them sent pretty unfriendly emails.

I literally got bullied by people who called themselves "the community" because they weren't happy with my copyleft license and the fact that I wasn't implementing their feature requests for free.

Happened to me too! Guy posted asking kinda rudely whether I was going to fix a bug. Told him I'd be happy to accept a PR for a fix. Never got a PR (project has been dead for some years now - just lost interest).

Auto-reply with the LICENSE.

I don’t understand what the downside of this is. That’s hilarious for them to expect, and you’re free to ignore them, take their suggestion and work on it, help them.

I'm sympathetic to FOSS developers but struggle to understand this, maybe because it hasn't happened to me. But, why is this a mental drain? Is there not a simple solution? Reply with the license, "comes with no warranty," "you're free to fork," close issue and move on? I suppose in aggregate it could be draining.