I understand the golf carts are not free, just as the dogs are not free. But the opportunity to have both is a benefit in itself. So the dog fee and cart fee is just part of the expense, no different than park tickets and dining.
I suspect, that part of the "niche" that people are referring to (and, I admit, I am probably in that group) with CFW may be more geographic than anything. I suspect that a large number of cash CFW visitors are those within driving distance that come to the Fort for a few days of fun.
Similarly, I think that if you are within driving distance of WDW (say, any of the Southeastern US), the calculus is much different. First, CFW has the unique advantage that if you are driving, you can pull up basically to the front door of your unit. Other than the SSR treehouses, no other accommodation offers that. I suppose SSR and OKW (and to a degree, AKV-Kidani) are "close" parking, but not right at the door. Also, if you can drive, then, quite honestly, you probably could care less about the transportation options, other than to MK, because you can just drive there, and for MK, there is boat transportation.
I also think that with the golf carts, if you are going to the Fort often, and you are within driving distance, you are probably considering purchasing your own golf cart. It would only take 3-4 weeks of renting to get into the territory of just having your own. I know that this is something we are considering...