I'm trying to avoid the "bait" as well as other smart parents, but had to put down my popcorn to comment on this. In the early 70's, there was one park. If there was one park now and I was going to Florida for a week, sure, my oldest could handle the Magic Kingdom spread out casually over 3 days.
With the increased number of parks and the increased number of park attendees, it is much more tiring on the little ones and much easier for the rude
non-stroller pushers (yes, they exist, too) to knock little ones down or cut between them and their parents. It can be very hard to get reunited with a child when they are being cut off by a streaming sea of people.
As always with this type of discussion, you've left no middle ground; no gray area. It's funny how black and white things become when you're trying to support your argument.
What about the child who is tired and napping in a stroller while their parents are taking a leisurely stroll around-the-world at Epcot? What about a family where a younger child doesn't want to walk anymore but an older child and the parents are still rested and ready to continue exploring the parks?
The real problem behind all of these "I hate X people at Disney" posts (be it people in wheelchairs or strollers, smokers, people who don't "continue to the end of their row", people who cut, etc...) are the rude people who don't know how to behave themselves in a public environment. The more people you add to the mix, the more you're going to run into it -- at theme parks, at malls, and even *ahem* internet message boards.
The best thing to do rather than condemn those who are polite, courteous and follow the rules, is to continue acting the right way yourself and enjoy your vacation.
If it's a serious enough offense that it needs to be brought to someone's attention, do so; it's better than getting in a fistfight in front of your kids, or someone else's, in the happiest place on earth.