Something like "In years past, many emulation projects were more niche and development done as part of a scene rather than collaboratively. Maybe that early history played into Dolphin starting out separate and then never having a good opportunity to merge its already developed codebass with MAME/MESS?" might come off less aggressively as well as focus the discussion around substance, if it were to be the original comment. Hopefully you can agree that it's a lot easier for meaningful conversation to form around that while, on the other hand, it's a lot easier for an emotionally charged conversation to form around a statement starting "Probably a combination of NIH syndrome, not knowing other projects exist,". Both statements might have genuinely seeked to make the same intended argument, but had completely different approaches are what make it interpreted as insults/flamebait vs well intended conversation, not the personally perceived factuality. Similarly, past experiences (second or third party) with other developers who had infighting problems is not an excuse to argue that's the problem with other developers you don't know while expecting it to be interpreted as well-intentioned, without a particularly deep explanation. Those kind of claims leave little in the way of content to respond to and invokes only emotional responses, which is precisely what flagging is for.

It wouldn't necessarily make it any more true as to why Dolphin is merged with MAME/MESS currently though. Dolphin has been an extremely collaborative open source effort over the years and went through multiple rewrites with hundreds of developers who were well aware of MAME/MESS (as well as other projects like retroarch these days) and still kept it standalone. What it would, however do, is be a well received comment and open the floor to earnest responses which could earnestly talk about those thoughts with more direct knowledge of the project. The other comments did a good job of covering technical reasons this kind of merger wouldn't really make sense, so I'm not going to duplicate that conversation here, but the comment being put next to them likely amplified that it seemed like a particularly unfounded take of the Dolphin team.

None of this is to say any of us here are perfect, me very often not, but just because you are asking why it was flagged so heavily and nobody else gave any explanation.

Even if you disagree with every last bit of the above though, please keep in mind many long time members of the Dolphin development community are active here on HN and they probably don't feel great reading comments from people they've never interacted with assuming these kinds of things (e.g. infighting, guarded about contributions, unaware of other popular projects, motivated by NIH as a primary reason) about them.

Maybe you should have just said something instead of kneejerking the flag button then. This whole conversation wouldn't have needed to take place.

I would have been happier to have had the record set straight (from the GC perspective) last week than having to repeat my earlier opinion of my personal experiences with the NES/GB/SNES communities.

The comment was already "dead" (hidden by default for low score) by the time I saw it (I have the "showdead" setting enabled, which enables users to see and second-chance review dead comments in case they think they might be "vouch" worthy) and it's generally not advisable to interact with the content that caused a thread to be flagged/dead here, beyond the second-chance reviewing. As a note, it takes many flags and downs combined with a lack of vouches and ups for a comment to reach and stay in flagged+dead status. Well, that or a moderator action, but you'll usually get a comment and/or email from them in that case.

In general though, what you say is true - the community guideline is to respond to the strongest plausible interpretation you can come up with and engage with that rather than downvote/flag, if you can. I've found sometimes, if my comment was deaded as being particular poor taste or flagged out as blatantly against guidelines, I might not get any responses as to "why" since many consider it obvious or have a hard time coming up with a constructive way to respond. Sometimes they are right, I look back as simply having woken up on the wrong side of the bed with the problems being truly obvious the next day. Other times, to counter this occasional lack of feedback when it isn't obvious to me, I take to editing (or self-replying if the edit window is closed) a genuine note like "My comment is being taken poorly, could someone take the time to explain why as I didn't mean it to?" often gets genuine responses. You seem to have found that out on your own as well, albeit here in a separate thread, and that's why I apologized for not realizing you were looking for feedback.