Another thing to consider, and this is just me hating the Nintendo revisionism that has happened over the last few years, is that the biggest and best developers were making games for the PC, Amiga and Atari St (throw in C64 and spectrum etc) and pretty much ignoring the Nes or doing very late ports to it.
Besides the japanese developers like Konami and Capcom, you had alot of third rate (LJN) type developers making shovelware for the Nes. The quickie movie licensed stuff like Back to the Future or even Fester's Quest.
Whats even more interesting is that you have youtube channels that look at the shovelware games on the Nes as serious games that need to be considered simply because they are part of the Nes library. Most of those games were very quickly made and done to turn a quick buck and don't deserve 30 minute retrospective videos.