I put quotes around "opinion". For instance:
"The blub language has the worst debugging support of any language I've used."
That is absolutely an opinion. It gives the impression of an informed opinion. Someone reads that and concludes that the blub language should be avoided because debugging will be a terrible experience. Perhaps what that person was saying is that blub doesn't have GDB support and in fact that turns out to be wrong. If someone asks for elaboration, they should indeed elaborate.
In the case of my comment, I just provided details so that everything is on the table. None of the other things you've asked for are relevant to my original comment.
This is not sea-lioning:
Person 1: I really think X is bad because A, B C.
Person 2: I disagree, X is fine because D, E, F.
Person 1: eh... I disagree. And I think D is problematic too.
That's merely a civil discussion.
This is sea-lioning:
Person 1: I really think X is bad because A, B, and C.
Person 2: You're wrong. X is fine. Why don't you explain why its wrong hmm?
Person 1: I just said, because A B and C....
Person 2: A B and C are irrelevant; Why don't you explain to me why X is bad. You can't do it! You don't know what you're talking about!
Person 1: I'm actually an expert in X, I've worked on it for two decades. I don't understand why you don't see A, B, and C are problematic?
Person 2: I highly doubt you know anything about X. If you can't explain why X is bad perhaps its your own limited understanding of X. All you talk about is A B and C but you don't explain why X is bad!
(Person 2 isn't providing any real counter-arguments; they are just saying Person 1 is wrong, asking for additional evidence, and then rejecting Person 1's arguments/evidence without explaining why Person 1 is wrong.)
Keep in mind the stress here is on the personal opinion - and not statement of fact. For example, whether or not code has "cruft" is entirely a subjective manner. There is no objective measure of "cruft" in code. You cannot "prove" code is crufty. However, you can put a group of engineers in a room, have them examine some code, and they can establish a consensus as to whether or not code is in fact "crufty" despite there being no formal criteria to define it as such. Generally, it means "messy and difficult to maintain". If you are a core maintainer, and your job is to interact with this code on a regular basis, you're the de-facto expert on its quality (albeit with some personal biases). If you think the code you have to work on is bad, and people don't work on that code are saying you're wrong after just skimming it, it's going to drive you insane.
I wouldn't have taken issue with your comment if you had stated it that way. The problem was with classifying it as wrong to challenge something simply because it's an opinion. Ridiculous objections and ridiculous requests are of course not deserving of a response, but that's not how you phrased it.
A good example is this other reply to my comment: "Please explain, in detail, why you believe there should be a high barrier to entry for expressing opinions, how doing so would lead to anything but an impoverished marketplace of ideas" That is misleading because a reader will infer that I actually said either of those things. Anyone posting something like that should be prepared to justify or withdraw the comment.
What you describe is the usual case, so it's a reasonable thing to assume, but if we examine reality we can make a case for concluding in this particular instance it's reversed.
S. is a newcomer, ISTR he started out with XS just a few years before. I just spot-checked the last 200 out of 500 commits, not a single one touches the core C part, it's only documentation and release maintenance. I mention these not because I think they are strong evidence for the case that he is not an expert, but easily verifiable. nwclark, pevans, davem definitely got their fingers dirty with the core of the code base, and were (2 out of 3) also previous release managers, we should consider experts and not "just skimming".
> whether or not code has "cruft" is entirely a subjective manner.
This was not was the argument was about. It was rather: one party claims the cruft is a big impediment against improvements, the other party claims the cruft is not a big deal in that regard.
I am just asking questions.
P.S. My real opinion that this is very subtle, and it depends on what you're saying. As always, good judgment is essential. Some claims demand proof, others are more throwaway. The biggest pathology I see is where people think they should be able to say insulting things and not be called on it, as long as they don't address anyone directly.
I disagree with your assessment.[0]
Furthermore, the underlying reasons for that disagreement are (or should be) obvious. As such, I decline to elucidate.[1]
[0] See what I did there?
[1] Why should I be required to invest time and energy in explaining myself?[2] Especially if I believe my statement (I'm including this because I'm guessing it isn't, at least for some folks) is intuitively obvious.
[2] That's not a rhetorical question.
Essentially, sealioning (as understood in this context) in an attempt to suppress dissent. And that's bad, no matter what tactic is employed.
"Pi is not transcendental!"
"Wow really, I'd love to see the proof of that!"
"You're just sealioning!"
I'm not making any claim about which of these two patterns is more common or a bigger problem, but both things totally exist.
We can't defend every intuition or opinion we have ever mentioned. People can disagree and carry on with the business of life.
In that spirit, you're perfectly entitled to have a differing opinion from mine and I will defend your right to disagree with me or anyone.
I really wish this attitude would disappear from the internet. If you make an assertion, you should be prepared to provide the details. Nobody is forcing anyone to make statements of "opinion" in a public forum with high visibility. If you don't want to provide support for your argument, all you have to do is not post. Ironically, you posted this on HN, where there is an expectation of doing exactly that, and for good reason.
Edit: Since this comment seems to bother lots of people, note the quotes around "opinion" and my use of the word "assertion". My problem with the parent comment is that misinformation can slip into comments that are phrased as opinions.