The analogy for me in this "debate" if it can be called one is similar to music. Sometimes a great talent or a great song would get lost in the over production of a big studio. The best place to hear it is busker style on a street corner. Sometimes you hear one dude sing a little song and he's incredible. This is the great 2D platformer, and one of the few ways an obscure musician might get recognised and elevated to new heights.
But there are lots of buskers, and alot of them aren't that great. Of course give an ok busker's song the full production treatment of orchestra, sampling, marketing etc. and it can be ok and built for mainstream radio, but at it's core it's meh. This is the same as a lot of mainstream games.
Gameplay is just the technical proficiency of the musician. Yeah, I can tell they're a great guitarist, or they write great lyrics but frankly the style of the music just isn't my thing. Purely a taste issue no matter how good a musician they are. Sometimes the producer takes a great song and ruins it, like Mass Effect shoe-horning in Mako missions, then planet scanning? But I can ignore the crappy "drum-beat" because I like the chorus... as it were. Also it can be a crap song but production makes it digestible, "Hit me baby one more time" by Britney was pointed out to me by a DJ as a well produced song but in reality fairly crap. Next time I listened I understood exactly what he meant. Modern Warfare 2 fits this bill for me.
So nostalgia doesn't come in to it. It's like saying "Wow, remember when you could only hear music on cassette tapes and then it was only ever one person with guitar or piano?" That's just luddite thinking. It doesn't make it better. And people who claim it's more "pure" sound just like music snobs who want to appear cool by saying "Yeah, I only go for busker music, anything else is a sell-out to evil music corporations and is turning to the dark side.... if you like Girls Aloud your a plebian sheep" just before I head-butt them.
Sometimes I want to listen to Blind Lemon Slim, but I also want Jack Johnson, both simple singer-song writers well played. Doesn't mean I like ALL solo artists, and it can be new or old. I sometimes like ELO, huge production but also good music. And yeah, Girls Aloud are a horrendous marketing gimmick but sometimes I want big production which makes it all sound better.
Good gameplay is good gameplay, doesn't mean I have to "love" the game because they were clever. And I like good games regardless if it's a stripped back, low-production 2D platformer, or a multi-billion dollar project funded by NASA. And I hate bad games that feel like a cheap cash-in, no matter what the production.
And the whole "Lost innoccence" is just a archetypal theme in music, books, art, film, and games. It's a separate entity to 2D platformers. It's as reliable a go-to story type as the love interest of mario and princess peach (poor working class guy chasing the hottest girl they can find).