Short answer: yes. We still need to think about and work on this.

Statistics are great, and I am a firm believer in data-driven behavior for most things, but numbers don't work so well when it comes to feelings.

If some new person comes to Stack Overflow and their own perception is that they haven't been welcomed, then the site is unwelcoming, regardless of how well or poorly the interactions they were involved in might be quantitatively scored.

As Abraham Lincoln would tell you here, there will always be some people who individually think the site/network is unwelcoming. It becomes a problem if the number of those people grows to a certain size, or those people start convincing others about how the site feels.

An alternative, slightly more concrete argument: it doesn't take a huge percentage of "bad" comments to make a site feel unwelcoming. If most of the content someone sees is unremarkable, but there's one comment that makes a new user feel uncomfortable, that's the one they'll focus on; it's just human nature, not a flaw of the user. Kind of like why newspapers don't publish stories about "dog bites man", only "man bites dog".

It's just not memorable when things are boring or quietly work the way they're supposed to. It takes something unusual (either good or bad, but "bad" seems to take less work) to make a stronger impression.

Short answer: yes. We still need to think about and work on this.

Statistics are great, and I am a firm believer in data-driven behavior for most things, but numbers don't work so well when it comes to feelings.

If some new person comes to Stack Overflow and their own perception is that they haven't been welcomed, then the site is unwelcoming, regardless of how well or poorly the interactions they were involved in might be quantitatively scored.

As Abraham Lincoln would wouldn't* tell you here, there will always be some people who individually think the site/network is unwelcoming. It becomes a problem if the number of those people grows to a certain size, or those people start convincing others about how the site feels.

An alternative, slightly more concrete argument: it doesn't take a huge percentage of "bad" comments to make a site feel unwelcoming. If most of the content someone sees is unremarkable, but there's one comment that makes a new user feel uncomfortable, that's the one they'll focus on; it's human nature, not a flaw of the user.

It's just not memorable when things are boring or quietly work the way they're supposed to. It takes something unusual (either good or bad, but "bad" seems to take less work) to make a strong impression. This is why journalists talk about "dog bites man" not being particularly newsworthy, while "man bites dog" is.

Pithy wrap-up about negative perceptions: it's not always our fault, but it is always our problem.

*: Actually, it turns out the "you can please some/all of the people all/some of the time" attribution is disputed on Wikiquote.