You're so close to understanding.

you've complained they're selling both too many and too few paid ships.

No, they said non-existant ships are sold out for 1k. They're talking about how easy the playerbase is to milk.

they want there to be late-game ships in the universe on launch day

Can you buy the ships with in game currency? If not, why the fuck not? If so, let them grind for it. I promise the players have plenty of time before release.

they don't see any advantage to releasing sooner rather than later.

And herein lies the problem. The pledge ships are supposedly just to fund early development and will not remain after launch because that would make the actual game pay to win. Right now it's just "pay early to win" which is better somehow I guess? But the point is they've made over 800 million goddamn dollars from that. Why in the hell would they EVER release this game when they have people shoveling over hundreds and thousands for in game items? Blizzard, EA, Bethesda, ubisoft, every big dev is looking at this macrotransaction system and frothing with envy. If they release the game, that kills their golden goose and dumps new players into a game they'll have to grind for months or years to achieve what early players achieved by opening their wallet. And the new players simply won't.

So you're almost correct about having a no incentive to release early, it's a negative incentive to release. They'll never do it. They keep expanding the scope and changing the roadmap and players keep coping and shoveling money into the fire while they play what is essentially a very good looking tech demo with no depth.