Thing is, you'll hear about GM:S HTML5 games being licensed left and right. There's even...that one guy...who claims to make tens of thousands a month licensing HTML5 games made in GM:S...though personally I think it's all bullsh*t to help push his book filled with common sense marketing stuff. Anyway, what makes that so different?
I reasonably certain that I've worked with a few of the publishers TrueVallaha has - the claims aren't that outlandish, my revenue on licensing alone is comparable.
Does C2 limit publishers?
Straight out the door you've lost access to what I like to call flip-publishers, these guys take your game, whack their "propriety software" on it (usually cramming as many interstitials as possible) and throw it on their portal. These guys have no time for C2, they're after the fast buck. They buy in bulk and it shows in their pricing - you're not getting more than a few hundred dollars for this.
The bigger players actually care about your games, and many of them are well aware of C2. Even a cursory look of popular portals and source-flipping sites will show you that ".capx" is quickly entering common HTML5 parlance.
Does C2 limit you?
Not so much, but always establish up front, before any work is done, that the source will be .capx - after that, you'll have a great time.
...Until next year when the source flippers and reskinners have well and truly ran the market into the ground - time to start to learning casual-style vector art folks, that's where the money's going to be....