So there are several things to consider in the competitive environment, and unfortunately not all of them are cut-and-dry. The first thing we have to say is: what is our objective when making a competitive ruleset? We are trying to develop a methodology of testing skill at this game. Which parts do we feel represent skill? One could make an argument for everything that is in the game, but arguments have been made against the rarer or weirder parts of the game for a few reasons. Either they take control out of the hands of the players thus reducing the overall proportion of skill in a match's outcome (stage hazards, items), they reward knowledge of such irrelevant parts of the game that more people disapprove than approve ("gimmicks", time/coin battle), or they change the flow of the base game mechanics that we intend to keep (items, weird stages).
The last one is the argument made for trimming stagelists. And especially in the other games when we have to make do with whatever stages God Sakurai left us, many of those weird stages that were "good enough" ended up in the list. So many people make the argument that since we can add in whatever stages we like, we should do away with those "good enough" stages. Instead, PMDT have simply been changing the weird aspects to make them more manageable, like preventing Wispy from blowing you off the ledge, giving Randall an indicator on both Yoshi's stages, and straightening out the stump. So why not use them?
Well then we get into the problem of tournaments needing to save time. This is a serious practical problem that is often addressed by reducing the stage pool to ~10 stages (somewhere from 9 to 12 is what I usually see). I do not believe FLSS can solve this problem, in fact I think it makes it worse. Is there a way to make all 17 of those stages work with a ban system to accommodate our time restraints? Probably, but even then we still have the following problem.
That stagelist may not be fair. I see 5 small stages (YS, WW, CS, MC, GHZ), 5 medium (FoD, BF, Lylat, YI, SV), and 7 large (PS2, FD, Skyworld, DS, Norfair, DL, DP). I also see 1 no-platform stage (FD), 4 sometimes-platform stages (Norfair, DS, SV, GHZ), 7 close-knit platform stages (BF, YS, WW, MC, CS, Lylat, YI), 2 spread-out platform stages (DL, Skyworld), and 3 somewhere in the middle (PS2, FoD, DP). You don't even have to agree with my categories (and most people won't!), which illustrates my point: Not only does this make choosing a stage very complicated and complex for the players (costing time), but the amount of work it would take to go through and make this stagelist fair is not worth it when there are other problems. Like...
Many people don't like all of these stages, and for different reasons. Some don't like slopes, some don't like moving parts, some don't like weird layouts, some don't like ledges with lips, and some don't like stage hazards (Fly guys, balloon, Skyworld platforms, Wispy). Some people will have to auto-ban these, so at some point why are we including them in the list in the first place? These players feel that these are not part of the way the game "should" be played and thus not part of the ruleset, so at that point why are we giving an advantage to the players that do like these odd elements?
Ok now that I have all of that out of the way, I can actually talk about how I feel personally. I think all of these stages are close enough to the core of Smash that they are all viable. Unfortunately, as I said before, FLSS is time-consuming and the full set of stages may not be a fair stagelist. That's why, at Smashing Grounds in MA, we rotate the list every few months. We use all of those stages at some point to give our players exposure to them in case they go to other regions and to keep things fresh. I think this is as close as you can get to using all of the stages. Oh, and I think you forgot Smashville on your list and put Yoshi's Story twice. I also assume Yoshi's Island 2 means Yoshi's Island.
