1) Afraid of dogs? Don't go to the resorts that allow them.
(On that note, do you go to parks? Use public sidewalks where people walk their dogs? Same thing.)
Sure, as long as it remains limited to just 4 resorts. But that wasn't really my point when I mentioned the terrified toddler thing. The point (for me) isn't the impact on individuals who might have made a different choice, but rather the impact on Disney as a business. Because people who are allergic or have kids who are afraid of dogs are still going to go to those resorts, either because they have no idea that dogs might be around, or because it's the only available room on site and they assume that the dogs won't be a big problem, or because the price is right and they're willing to take the risk, or whatever. And when they do, whether they knowingly made a poor decision or not, incidents are going to occur.
If you take your kid to the local park and a dog jumps on him and he refuses to ever go back to that park, it makes no difference to Disney. But if the same kid ends up in an elevator at WDW with a dog who barks and jumps, and the kid freaks out and then conflates "Mickey Mouse" with "scary dogs" for the next five years, that's bad business for Disney.
Farfetched? Maybe, but I don't really think so. Again, fear of dogs is not at all uncommon in little kids who don't have dogs at home, and some kids can fixate on what might seem like a minor incident for a long, long time. Putting aside damage and cleaning costs, is $50 a night enough to offset whatever business is lost because the Smith family decides to wait a few years until little Johnny is over "the dog incident" before heading back to Disney World? Hard to say, because those impacts are not easily measurable. Doesn't mean they're not happening.
Or if the have a fear of seeing a dog.
These were brought up as concerns.
I don't imagine many people are struck with terror at the mere sight of a dog. But the ones that run at people, jump, and bark... yes, that can be scary for some. I'm sure dogs will be required to be on leashes, but I guarantee there will be the occasional incident when a dog is let off, or is on an excessively long leash, or otherwise gets away (oops, the 5-year-old dropped the leash). It's not Disney's fault if that happens (or not directly, anyway), but the fallout is definitely their problem.
For the record, this isn't personal for me. My kids are past the age of being afraid of dogs, nobody in my family is allergic, and we generally stay at DVC resorts anyway. I'm not a dog lover, but neither do I dislike them. Given an equivalent alternative option, I'd pick a "dog free" resort over pet-friendly every time, but I probably wouldn't make a huge point of avoiding the dog resorts under the right circumstances. I still think that this is, at best, a questionable business decision.