Basically, for a few years in the late 90s PD type games were being released as commercial, but fortunately the likes of Clickboom, Hyperion/Titan, Sadeness, and to a lesser extent, Vulcan, showed that despite the Amiga's lack of power, it was capable of a lot lot more!
I think this happened with all system when they are not the "most popular system around" anymore .. we see lots of really "push the hardware to its limits" games but also lots of crap games being released.
I think this happens because users who love the system just go and try to make their games, as the top developers aren't doing it anymore. Sometimes you have guys who can create really good games (like Clickboom), and others who cant (like the guys who made olofight).
I see this happening with the MSX too.. there are some really amazing games being released, but many incredibly crap ones, and because people still buying MSX games today are MSX lovers, they will usually buy ANYTHING that comes, just to support the system.