Its not burying your head in the sand.

It is, just because people haven't reported it doesn't mean they haven't experienced it. Maybe 90% of the people experienced that bug, but only the ones on Linux reported it. It had to be a very big number so that statistically less than 6% of the population experienced it enough to report it. Think about it, what are the chances someone specifically would get a generalized bug? If it's 1% the chance that that 1% happens to be within the 6% of Linux users is very slim, for that to happen 400 times it's inconceivable, those bugs were widespread, just not reported.

If it is isolated or people just don't care? Then... it kind of doesn't actually matter.

Again, you're making an assumption, the bugs were probably not isolated, and we don't know what they were so maybe they were big deals, just unreported big deals.

You scan the forums and optimally have community managers/PR people to do the same to keep an eye out for "This was weird?" style comments but you mostly focus on the stuff that naturally rises to the top or that you identify as an issue.

So you're saying getting a bug with reproducible steps is worse than having to hire people to search the internet for posts and then pay engineers money to try to reproduce, so that you can finally have the same thing you would have gotten for free? Dude, sometimes people say "the game crashed, piece of shit" and that's all the info you get in a forum, whereas a bug report is more akin to "When talking to NPC X the game crashed, here's the stack trace, here's my save file right before, I've confirmed that going and talking to X immediately triggers the issue", but you do you, hire a community manager full time to read posts in case someone says the "the game crashed", then pay a QA to sit on their hands until such report comes and then spend months to try to reproduce the issue, to finally get the same bug report that some random person would have given you for free.

The more bug reports you have? That is engineer time spent assessing what is and isn't a priority.

No, engineers fix the bugs, project managers asses whether a bug is or isn't a priority, or you thought their job was just to guide you through scrum practices?

And the sad reality is that it is a LOT easier to say "we have our five thousandth number one priority" rather than to say something doesn't matter.

All you have to say is "your bug has been reported, we will look into it".