Sure, I mean, the DM gets to decide. But I think that was just them trying to point out that the feature is a PC feature, and therefore the player should be invoking it (to save the DM's headspace, not to usurp their power).
Yeah, that's an odd argument to make.
That seems like how it ought to go to me.
That's simply not how "working WITH" a person... works. There's back-and-forth. Anyone who can't handle that ought to go find something else to do with their time. That's not gatekeeping. If you can't play well with others, you shouldn't play games. Or more correctly: If you can't learn to. Making mistakes is okay. Never fixing them is not.
I mean, I won't say that I've never seen it happen. I've played with about a thousand people all told, over ~37 years. But I've never seen them 1) Refuse to learn to play nice with others OR 2) Not figure out that sort of spit is not going to fly.
They'll learn, or quit playing (with me, at least!)
I've never even needed to kick anyone out. They learn to play nice with others, or they leave.
This is where you and I differ. I never think of a suggestion of "A DM ought to do X" as meaning "And players don't have to do anything!". Players ALSO have things that they ought to do too. The #2 thing (after "play nice with others" would be "Ultimately accept whatever the DM decides. You can make your case, but it is YOUR job to back down.".
If I was playing, say Oofta's game, and I was zapped off to some other world or time, while playing my Sailor, and I said, "Can I find any sailors to carouse with and make a contact" and he responded with "No, that's silly. This is a desert world". And I couldn't get anywhere with, "Howabout a lesser connection with that guy that ships freight on Mastodon-back? That's similar to a sailor, but without the ocean." And he said, "Nope. They think your sailor-ways are weird and standoffish. No contacts for you!" Well, I'd simply have to suck it up.
That's playing nice with others.
If you're playing a sailor in the desert, it's likely because of party choice to go to the desert. Beyond that you likely have better knowledge of certain aspects related to sailing and shipping, you just don't get any background feature benefits.