Because the authors don't owe you anything. You aren't giving them a single thing. They don't have to justify a thing. There is no SLA, no contract, nothing.

Feedback is fine, but there are so comments being things like "ermahgerd I paid nothing for this thing and a feature wasn't working What the actual F!". Go file an issue and fix it yourself buddy.

There seems to be pervasive opinion among FOSS enthusiasts that the software being free and volunteer made is kind of get out of jail card for not only criticism, but often simply just feedback.

I deeply appreciate that FOSS exists. But - subjective feeling - in general it always had certain reputation for jankiness and user unfriendliness. Sniping down feedback "because the software is free" certainly contributes to that perception. If I have a choice between free, volunteer made software that's unreliable or doesn't even work for some of my use cases, and a commercial, but non-free product, I will be pragmatic about it and choose the latter.

As an open-source developer, feedback is about 1% of what I need. Contributions are the other 99%. However, the reality is flipped where what I get is 99% feedback (issues/feature requests in the issue tracker) and 1% contributions. And this is not a "significant regression", I use Inkscape very often for graphics work and it works great for me. And it does not "justify" regressions, but if you are not willing to fix it yourself, you have no right to do anything other than kindly request a fix, not complain about it. And btw, I don't search hacker news for "feedback", I search my issue tracker.

There's already feedback in the gitlab issue that the top commenter linked. Their HN comment isn't really adding anything

Hit me with the downvotes, but the only thing their comment has contributed to is causing arguments.