Let's see if I can address your points OP:
1. Everything seems to be US based - well yes, MMM is from the US so his postings are based on that perspective. Similarly, most of the people on the forum are also from the US so that's the perspective most often represented here.
2. It's mostly higher-income earners on the forums - Yep, that's how it's skewed.
3. Is there nothing for others here? Quite the contrary, there's lots for people of all means. In fact, you've already admitted to embracing some of the core tenets of the mustachian philosophy - riding your bike instead of having cars to cut down on costs, increase health, and reduce damage to the environment; minimizing living costs by keeping living situation from expanding simply because you "can afford a bigger place" (living at home instead of cutting your savings rate so that you could have a place of your own in your case), avoiding going out to eat and instead cooking food yourself, etc.
Just because you already have implemented such things doesn't mean there is no where else you could optimize your spending, and it doesn't mean that you need to do more or that the forum's lack of providing you (in your particular situation) with a bunch of other significant ways to cut expenses is an indication that it isn't for you. Quite the contrary, I think it means you've found a place with like-minded people who you can help with your viewpoints and who can help you with theirs in the future. That you don't see any advice you need at this moment doesn't mean you won't in the future or that you couldn't be one of the people providing advice to others here.
Welcome to the forums.