When I saw the thread title, the first thought that came to mind was team typing.
In the anime, some main protagonists always have the conventional Grass, Fire, and Water type-pokemon in their teams. Some examples of Purists would be Ash/Red, Gary/Blue, Cynthia, Bianca, Barry, and Cheren.
So I would say that I HAVE to include a Grass, Fire, and Water type Pokemon. So in that respect that is what I think of as sticking to that standard and nostalgic conventions of a protagonist/champion team.
But as a GEN 1 Purist, I would say I am not at all. I love GEN 1, but I love the other GEN's as well.