I remember games like R-Type fondly. I'm too young to remember the originals, and my family didn't have consoles until I was several years into my elementary school career, but I think that hte formula is quite classic and potentially timeless.

One of the issues that I see with it making a resurgence is that it's the sort of game that requires a lot of effort to get right. In theory, you could design an R-Type style game on a fairly low budget, but the actual design has to be done by skilled people. If you have a novice do it you wind up with a bunch of issues.

Another thing is just the styles. People are into bullet-hell games, which are enough like R-Type that they draw off a lot of the equivalent market share, but they're also niche. Someone like me with the reflexes of a narcoleptic gerbil doesn't do well with them, and the mainstream appeal winds up lacking.