I think VCS Pac Man is a horrible game. If someone else thinks it's a good game we merely have a different opinion, and that's fine.
However, the idea that "well it's not a good Pac Man game, but it's a good game" is nonsense. I think my toaster is a good toaster, but my toaster is not a good car. Obviously it's irrelevant that it's not a good car because it's not supposed to be a car. Pitfall is a great jungle adventure game.. if they called it "Superman" it would be known as the game where Superman wears green and can't fly.
The game is Pac Man because it's supposed to be Pac Man. It does a terrible job at being Pac Man, and is therefore a bad game.
Also irrelevant is the behind-the-scenes HSW only had 6 weeks, 2K ram or whatever, blah blah blah. That game sucks.