Everyone likes to think that they'd make the perfect game if they could mod it, but there's basically nothing that everyone will agree on when changing a game with millions of players. For every change you make, you alienate some segment of the population. And of course, in this situation the moment you make a single modded change you remove 99% of the possible players of a game, since they will never be interested in making that level of effort. Project M gets around this constraint, Melee cannot. But then, Project M does not pretend to be the "true" version of Brawl - they even gave it its own name instead of all the Brawl+s. The feeling that I've always gotten from people is that they think their idea of what is important in Melee is the "real" or "true" version of the game, but I hate that approach.
Video games are art, to some extent, and not science. We're not the artists for the game's framework and tools - we're the artists that paint with those tools. In this case, there are some moldy splotches on the picture that have to be cut out. But maybe while cutting out those splotches, I think, "Man, I really don't like having that tree painted like that" and I cut that out, too. And then, I look at a flower and think, "I could do a better job there," and I paint over the flower. At what point does it become my own creation instead of the original piece of art? We've already lost so much just from having to cut out the mold, so why keep messing with the artist's original work?
If you ever see casuals comment on the tournament scene, their primary criticism boils down to "that's not the game we play." They're right, of course, and it will always be that way on some level, but at what point does it literally become a different game? Modding is, in essence, what the neutrals-only, items-off stagelist already does. It takes out a significant chunk of the game such that it is almost unrecognizable to the common player.
We really tried to find ways to keep items in during the early days. I think that's the biggest chunk of the original game that we've lost, and the biggest point of contention with casual players. At FC1, we had Items On for first-round pool play. Still caused way too much havoc on results. At some point, you do cross a line that competitive players are not willing to cross when it comes to randomness, and that's fair. The Turnip Threshold is a way to try to talk about that line in a logical way Would love to see someone try to quantify it.
Anyway, I have a lot of personal beliefs about the topic, but that's why this is such a contentious topic. Everyone has a lot of personal beliefs about the topic. That's why I always opposed a standardized ruleset for the community, especially for a game with this many options built into it. I'd love to see a major, FD-only tournament. That'd be extremely interesting as a one-time exercise - players would have to practice for it and you'd see the real state of so many matchups on that stage.
That's probably well enough on my wall-of-texting.