I wholeheartly agree with the posts on this thread. It is the best of BOTH worlds. If you want it everyday, then you pay extra, if you don't then you don't pay for it in the dues.
In 1992 when we were staying at the Poly, our oldest boy was just 6 months old and took 2 or 3 naps per day. Maid service was a problem as they wanted to get in to the room EVEN if we hung a 'privacy' tag on the door knob. (they probably thought we forgot to rehang the tag inside the door)
The previous poster is also right, the dues reflects the actual cost of maintaining the resort plus a fixed percentage management fee paid to Disney....there is NOT extra 'fluff' built in to cover daily maid service.
The washer and dryer in the larger units certainly eliminate a lot of the need for daily maid service anyway. We just ask the kids and guests to trow their used towels in to the washer when they are done bathing, and run the unit while we walk out the door in the morning, when we return we transfer the load to the dryer.