Ok, so you're not the typical, average off site guest. It happens.
I'm talking about why Disney wouldn't care for throwaway rooms- not the good and bad of staying off site or which guest is in some way better.
On site guests, by and large- with some exceptions spend more than off site guests. Search "Disney on a budget"...see if staying offsite isn't the #1 tip you get on damn near every site you find.
I'd argue back that the majority of people willing to book a throwaway room are spending just as much, if not more, on disney property than a lot of on site guests. The reason people book such rooms is because they want coveted FPs and ADRs. They plan to spend a lot of time in the parks and eat and drink and buy stuff. They are often using the $$$ saved on accommodations to purchase stuff in the parks.
I have at least 1 ADR per day booked for our trip and plan on doing CS for one meal each day also. In addition we have MNSSHP tickets also. We are eating our hearts out in DW and planning on buying stuff in the gift shops for sure. I would totally agree with you that in general- offsite guests DO spend less $$$ inside the parks but I think us 'crazy throwaway bookers' are the exception.
DW will know that I'm a 1 day throwaway with an address that is 2000 miles away....so they can deduce I'm a throwaway renter. I will have my MBs on the entire time so they can see what I'm buying, where I'm eating etc etc. Same as everyone else. I have no doubt that in 6 months or a year Disney will be doing some algorithms to determine whether a minimum night stay should be required or not based on our MBs RFID information. If they do- I'm 100% on board with that. Booking a value for a 6 night trip STILL saves me 1000s. We also do stay onsite sometimes too- this time in a Saratoga DVC condo so we do split stays.