What it is is that you can also get a descent hotel in town where you are in better proximity to being able to do more things (i.e. shopping, eating, sightseeing, etc) than just Disney. And even when you are staying at a hotel in town as oppose to the one at the theme park resort, the theme park itself is not painfully far away (easily accessible by the MTR).
I would not suggest staying at the Disney hotel unless you are coming to HK only to visit that theme park. Even that I would find to be a waste of money/mileage/time just to get a plane ticket and travel solely to visit Disney especially if you're coming from NA or Europe. So for those with multiple plans/activities (including those with an included itinerary to Disneyland) with a few days in the SAR, getting a hotel in town is a much better option.