I wonder this too (Where is PC Gunjin, mostly).
I think the reality of it is though, nobody has the time to do games like that in a manner that will see them released in any sane time frame.
The longer you're stuck working on stuff, the more boring it can get.
Simple pre-crash style arcade games are simple enough that you don't get burned out on them.
Though, it's easy to get burned out on those too... (See: Atlantean!, lol)
While I wish Hypernova Blast wasn't another horizontal defender-like game for variety's sake (There's 4 horizontal shooter homebrews all in the works right now! -_-; lol), I will still happily grab it and play it because it's like Novablast on Coleco/Intellivision, and that shit was awesome.
and now I have even less reason to drag those pieces of shit out and hook them up, so this is OK in my book, lol.