I think this sort of ignores both the huuuuuuge amount of horrible shovelware the 2600 had and the fact that the NES got superior ports of almost all worthwhile 2600 games.
Yes, game design shifted towards longer, more complicated experiences during the 3rd generation, but the 2nd generation classics were still very much alive on the NES too.
IMO, with NES you get the best of both worlds. If you want the simple, pick up and play style design of the 2nd gen, you can just pick up those games on your NES and play them. But if you feel like playing something meatier, SMB 1,2,3, Zelda, Castlevania ect. are there for you.
And while the first RPGs on the NES have all been uniformly eclipsed by their successors on the SNES, the original Zelda has held up incredibly well and the genre as a whole really got it's start on consoles with the more powerful hardware of the NES.