Ive noticed that it's commonly accepted to have Wario Ware as a neutral stage.
I'm not criticizing the choice, and I don't have too much of an opinion on it honestly.
But I'm curious.

Why is this stage considered a neutral? Or, why should it not be considered a neutral?

I would like opinions.

Your patience for camping is insane :O

It's legal firstly because it doesn't do anything game-breaking.

It is a neutral though is based on the fact that a neutral list needs variety in layout/size. WW provides a neutral list with a smallish stage, and it isn't another BF. If you think that a neutral list may contain BF, FD/3DS, WW, PS3, and Yoshi's Story, we can see that BF and Yoshi's Story have the same layout. Yoshi's is a smaller stage so it gets through, FD/3DS are large. WW has a unique platform layout so it keeps everything from being a BF clone. In this neutral list, there are only 2 BF layouts. Finally, a stage list needs an odd amount of stages to facilitate striking. It's the best stage to put in that 5th slot on a neutral list if you assume the other 4 are given.

Thinkof Yoshi's Story as a smaller version of Battlefield with slight slopes, then think of Wario Ware as a unique stage that is also small. Based on the accepted stage list; we have two small, two medium, and one large stage. And the best part is that all of them have variety, so there is reason to strike each one.

I actually wondered about this when online tournaments were starting. I've come to dislike WarioWare as its layout definitely adds more sway on characters match-ups than other neutral stages. It's the smallest stage (this stage is definitely smaller than Yoshi's Story and 3DS), with close boundaries, and highly placed platforms. Marth, Zelda, and Lloyd just feel too good on the stage. They can chase down any character. The platform layout assist and protect their recovery. Marth and Lloyd have their Up-special tech with the platforms. Fox, Falcon, Mario, Pikachu, and Sonic feel heavily nerfed because of the lack of space to retreat when needed. And setup characters like Black Mage and Bomberman don't have time to do setups while being more open to rushdown. It's not a great feeling stage in my opinion.

So why WW over mirror chamber for that starter stage spot?

Mirror Chamber is a large stage with shorter side blast zones. This is a very strange contradiction to the other large stages that have larger blast zones. In addition to that the layout is more unorthodox with middle platform being lower and the side platforms being higher. Sure Wario has 4 platforms, but their placement is not as strange as Mirror Chambers; if anything it's more like Pokemon Stadium's platform placement (albeit more to the edge of the stage with another platform above each one).

Warioware benefits disjoints and upwards based characters. Its not simply rushdown, for example tails is not good in the slightest , warioware heavily benifits charecters with good edgegaurding games or vertical combos.

Magic mirror would be a intresting neutral stage, its large enough to be used as a campground, but gives viable escape options and rushdown options. The short blastzone gives a advantage to heavy hitters but the high platforms give lighter characters a secondary recovery option.

Its arguably tails best stage, but other than that the stage brings in elements that warioware lacks, and almost all the decent ones it has.

I would take magic miror oover warioware anyday as a neutral.

Here's some of the problems I have with Mirror Chamber:

1. There's a platform in the middle that I don't like because it makes for EZ tech chases and stupid setups.
2. The sides are fairly small, so a lucky hit near the edge can end you really early, but it's harder to kill off the top, so it favors characters with horizontal kill moves. DK's cargo throw to something kills at like 30%, but Fox's usmash kills at higher percentages than it usually does. This really hurts characters like Fox and Pika while really buffing DK and other characters with staple horizontal kill moves.
3. The bottom is weird for certain recoveries, so it nerfs characters like Mario that often ride the wall.

For these reasons, I don't think it makes a good neutral stage.

I dont play a lot of center stage and mirror chamber is all about center stage :p

I'll agree that middle platform height doesn't make sense. Tall character like Marth and DK can literally walk through the platform. They also can jab a character standing on top of the platform to fall out and frame-trap them into a grab. I would have figured that Mirror Chamber would be laid out identically to an inverted Battle-Field; 2 high platforms, 1 mid-level platform. If it weren't for Mirror Chambers' array of platforms being so low to the base of the stage, maybe it would be neutral. A pretty nice one at that.

Honestly though, neither Mirror Chamber or WarioWare are more neutral than Smashville, or even ToS.

Maybe so, but both of those stages are very similar to FD/3DS that there would be a loss in stage variety. Then, even though SV is very neutral, it all depends on how many stages the stage lists uses. If the neutral list was 7 stages then maybe there would be room for SV/MC but 7 neutral stages is a lot albeit not unprecedented.

Smashville is like super huge tho. Kinda wish mirror chamber was an inverted dreamland or something.

If there were room for 7 neutrals, then dreamland would have to be on that list.

Heres a thought, run a tourney with Smashville as a replacement for FD/3DS as one of the starters.

I really hate smashville but id rather have it in place of 3ds.