Is something stopping everyone who complains about deepbit from doing this on their own?

Is there any government regulatory body preventing them?

If they did this on their own and offered similiar or better features than deepbit, wouldn't miners move away from deepbit?

That's the thing, it's a free market, anybody can go ahead and actually make this and start a pool that engages in this.

Yes it may be hard to do, welcome to the real world.