No deep understanding needed why he didn't like Super Mario 64: Super Mario 64 was a big, empty game. A big empty game where you repeated the same levels over and over again.
I understand the technical aspect of it, as it was one of the first 3D platformers with big, open levels to explore. Rather than just rooms, caverns, and canyons, and corridors like others had been. But there just wasn't much there in those big open levels. So much open space.
Personally, that wouldn't be so bad for me if I was able to explore a new area each stage. But instead, you have to play the same level like 5 times over, which is just plain lazy game design. But since it's Mario, nobody ever mentions that it's lazy game design.
And where's all the power-ups?!
I'm also with him when it comes to games like Crash Bandicoot, Spyro, and even Pac-Man World. Those were fun 3D platformers. Granted, many of them didn't have the big open levels of Mario, but they were jam-packed with enemies, items, and secrets and such that kept you going. And you weren't forced to repeat levels.
That argument seems pretty unfair. They repeated the basic formula on Sunshine and Galaxy, except there was more objectives and more enemies. Still, it was open worlds with objective based gameplay. The same argument could be made for anything like GTA. Massive open worlds that are mostly empty and repetitious still the objective based gameplay is fun (to some).
I think Mario needed a change of pace as many games do. People complain about Sonic trying to change but it needed to change as well. Perhaps the dullest Mario experience for me is the Super Mario 3d World on Wii U. We've repeated that same experience since 2006, and it's just not exciting for me anymore. I want more of the open world objective based games.
I don't think I'd be as fond of Mario 64 if it had been a Crash Bandicoot type of game. Obviously it couldn't be Hyrule Warriors or Elder Scrolls being a cartridge based game in 1996, but had the potential to be something entirely different from the past games and I'm glad they took that opportunity because I like the style of gameplay.