yeah, this "people will lose interest with long waits" is one of the reasons for why Alex has no intention whatsoever to use steam early access or similar. when you buy Starsector, you buy the game
in its current state more so than any promises of what's still to come at some point in the future. and seeing as how i already got hundreds of hours of entertainment from ~0.5.4 to 0.7.2 (not to mention getting to know a bunch of great people in this community
, i'm personally quite satisfied with the value i got out of my 10 bucks! ^^
and after the eventual full release (which will almost certainly include a steam release), the game doesn't need "new content, added on regular basis". in fact, the vast majority of b2p single-player games do not have major content additions after release, outside of payed-for DLC. patches to fix bugs, balancing issues, etc; yes. though even there Starsector's alpha versions are more polished than maaany 'finished' games.
i understand the concern, and i'm sure all of us here want Starsector to be successful, but i don't think its successful future will be hindered by the current long wait between patches. and it's already sold thousands of copies (we don't have official numbers from Alex on this, but iirc estimate based on mod downloads is minimum of 5k, probably more like 10k+) even before being available on any of the big stores.