I'm not saying this is the way it ought to be, but just how I think it currently is.
I know, there are people who go to Anaheim and never step foot off of Disney property. And there are people who go to WDW and still spend plenty of time off-site. But WDW is practically a city in and of itself. As a result there's a perception amongst Disney brass that they've got to invest more TLC in Anaheim in order to keep people coming and staying, whereas in Orlando, the relatively small financial investment that is Disney's Magical Express does most of the heavy lifting.
After all, in Anaheim, the footprint of DL is smaller, it's right in the thick of things, there are only three onsite hotels, only 2 parks. It's much more a PART of people's vacations, as opposed to WDW which can consume entire vacations (plus make it seem more cost-effective to make the trip longer, or come back more often). It's not necessary in WDW to make you WANT to stay, just make it seem more COST-EFFECTIVE to stay, and more difficult to leave.
Good proof of this: If you go to the citypass website, Disneyland parks are a big part of the southern California Citypass, along Universal Studios, Sea World and other parks. Whereas the comparable Orlando Flexticket includes Uni Parks and Sea World Parks. Wet 'n Wild. Maybe Busch Gardens. But No Disney World. Disney understands they're a part of a larger vacation on the West, but on the East, they can easily be the whole thing.