It was super (mario) controversial at the time, he put his career on the line and evangelical groups wanted his head, but he ended up being on the right side of history.
He showed that giant turtle dragon dinosaurs of any orientation can make it to the top, and be flung face-first into a spiky floating sky mine.
Mario may have laid the ground work but the genre didn't really solidify until the release of Castlevania 64 added 3 crucial elements:
Because of this I prefer to call the genre mariovanias