Well, sure, like any publicly held company, they're always thinking about profit. If not, the stockholders force the top guy out and replace him with someone who will make sure the employees are always thinking about profit.
But seriously, Disney needs to keep their resort categories differentiated, to encourage people to stay at the 'better', more expensive resorts. You need to give people reasons to stay at deluxes instead of moderates. Which is why deluxes get bigger rooms that sleep more people, queen beds, more restaurants, etc.
If all of the mods slept 5 per room, that's one less reason for guests to choose a deluxe resort.