Well, that does nothing for people bringing their own.
Having thought about this some more, I think it also stems from a variety of reasons. Economy, expansion of WDW, and the general mindset of people.
With the current economy, people want the most bang for their buck. That means touring the parks from rope drop to kiss goodnight. That means seeing as many attractions as possible. Of course WDW is much bigger now, it takes longer to see all 4 parks plus DTD, water parks, mini-golf, etc etc. However vacation time has not become larger. People still get so many weeks of vacation per year. So now you are trying to cram much more into the same period of time. Couple that with the instant gratification, go-go-go, bells, whistles, and lights, (and also paranoia) mindset of the current generation and you have a perfect storm of stroller use.
People don't want to let junior sleep in for a bit, go to the parks, take a break on a bench with a cold drink, see some more, go to the resort for a rest, come back later, and then go back to the resort at a resonable bed time for the kid. They want to see it all. Go, go, go!!! - of course your kid is going to be tired. Couple that with people not wanting to stop and smell the roses (so to speak) because it's not "fun". Just for kicks you throw in the parinoia factor - that touring a park is akin to a 90 day safari in the bush, and you have (as somone mentioned) people using the strollers as rolling supply carts for snacks, hand sanitizer, a change of clothes, water jugs, toys, first aid kit, etc. Maybe Dinsey could allow people to hire real Sherpas in AK.
Really though, people are the best judge of what their kids can handle. However if your kid can't handle something, you need to also ask yourself why they can't handle it. Maybe you are pushing them just a bit too far.
-dave