But to be honest, complaining about the environment is one step closer to a diva attitude that I think should be discouraged. If you're a fighter, it would behoove you to be able to adapt to your surroundings (especially since evidently MMA doesn't have the standardization of having the same competing environment everywhere).
It's going to get real ridiculous if MMA becomes like boxing where fighters will need to have long negotiations about the size and fabric of gloves prior to each fight.
There's nothing Diva about the legitimate differences between a cage and a ring. The way you move your feet and the way you can effectively grapple are significantly different between a ring and a cage.
You can sprawl against a double-leg in a ring but can't do it when your back's to a cage, and you it's way harder to complete a single-leg when the guy just digs his shoulders into a cage to prevent himself from getting rotated off-balance. There's a reason you used to hear a lot about a guy's great single-leg but the second Pride went under it became all about having a great double-leg. A lot of guys even have an easier time getting takedowns in a cage than a ring because their styles are built around the double-leg, and the drop-down-and-secure-your-grip-while-they-do-the-splits-and-try-to-break-the-grip-of-one-of-your-arms game is way easier to 'em than figuring out how to get your single-legs to be better or mastering counter-timing to ensure your double-legs work well (which, to be honest, it is.)
In a cage, if you want to use a good clinch game, a gigantic part of it is just pushing the other guy into the fence to neutralize a lot of the things they can do, since they'll be so upright and easier to work over; in a ring you have to work a lot more on holds and switching between grips because you can't just force someone up against the ropes as solidly as you can a cage. You also have a lot less time to work with to get a takedown from double underhooks in a ring compared to a cage for both of those reasons; the guy can sprawl their legs out and regain their footing and balance no matter where they are, which, for obvious reasons, leaves just wrapping one of your legs over theirs for a trip or dropping down for a double-leg much harder to execute.
If your takedown style is Greco-Roman and built around getting double-underhooks and working the guy against the cage while patiently looking for a takedown, you're gonna have a much harder time doing it in a ring. If you get put into a reverse bear-hug in a ring your options are way more open because you're not gonna be constantly wedged against something, so you can constantly keep your balance while working to break the grip (and even work for a double wristlock ala Kazushi Sakuraba). The only places you can wedge a guy up against something in a ring are the corners, and those are a lot easier to get out of because it's only four spots, and even against them they can sprawl.
Just mastering a single-leg and a double-leg to the point where they work against high-level wrestlers are things that take
years of practice and change in order to adapt, just as defending against them is; it's not something you can just pick up in a couple months. Expecting fighters to just be able to
do that is setting an unreasonable standard that next to nobody is going to be able to reach.