I don't what the problem is. They are extremely transparent with development and internal timelines. No one expects the game to be finished anytime soon, but there is continuous progress.
Yeah, as many backers exist that apparently delude themselves into thinking the game will be done soon, there are just as many that call it vaporware when there is clear progress every single week. They made presale money, sure, but it seems like the latter just can't comprehend that, just as with open source projects, the developers are building the game because they want to build it, not just because it will make money.
Also just because they want to build it doesn't mean they will ever finish. Nor does it mean that they're able to build what they've set out to build.
Anyone remember the DayZ standalone? People said the same thing about rocket. That he won't abandon his game. He cashed out years ago and the game is still a buggy piece of shit. And that's a far less ambitious game than Star Citizen.
Just because they "want" to build it, doesn't mean that they can or that they won't lose interest in a few years when the interesting bits are done and its just a long road of grinding to actually get something shippable.
(I'm not backer, just interested in the game)