To me, it seems like there are a few different issues getting jumbled together here.
The unlinked MBs and the throwaway rooms can be connected, but they don't have to be. I know many people (myself included) have used a throwaway room, but not unlinked bands. Others have used unlinked bands without a throwaway. For example, we had APs and stayed onsite four times in a year. We had four sets of bands, so for everything after the first stay, we could have set up new MDE accounts and used the extra MBs for SDFPs. We didn't do that, but that would have been an onsite stay sleeping in the room and having unlinked bands. Conversely, when we booked a throwaway for my SIL last fall, it was solely to get access to FP+. We didn't have fake people listed on the reservation or multiple bands per person.
The issues I've seen people raise are:
1) It's wrong to buy something and not use it to its fullest.
This just seems silly to me. I buy things all the time and don't use them. Nobody has ever suggested this was a moral failing.
2) Someone else might want the room you booked.
I don't understand this either. If they wanted the room, they could have booked it themselves. If it was open and available for me to book it, then it was available for anyone else. It appears that campsites are available for most of the rest of the year, so it doesn't seem that this practice has caused hundreds to be turned away from campsites. The same goes for value resorts.
3) A one-night reservation splits up a week and prevents someone else from booking a week.
A split stay that is just one or two nights in a resort would do the same thing, and nobody seems to think this is a problem. I don't understand why it matters if someone sleeps in the room or not, or if it's a campsite vs. a deluxe. The week is still "broken up" either way. If it's okay in one situation, it should be acceptable in the other as well.
4) People are stealing a week or more of benefits by booking for one night.
As mentioned previously, this is not true. They receive length-of-stay benefits. Parking and EMH are for the days of the stay. FP+ bookings are 60 days for the length of the resort stay. After that, it is a rolling 60 days. It's better than 30 days, but not as good as what someone staying onsite for a week would get. If you tried to sneak into EMHs after your checkout date or get extra days of free parking, that would be different, as that is not something you are entitle to have with your booking. The 60-day rolling booking window for FPs for the length of ticket IS included as one of your onsite stay benefits.
5) People are booking a campsite to get multiple MBs to make SDFPs.
I think this is likely a very small minority of those booking the throwaway. I also don't consider this synonymous with a throwaway (see beginning of my post). It seems most people do it for the MBs and the 60-day FP booking. I don't think I'd order extra MBs for fake guests, but the practice doesn't hurt me at all, so I won't comment. The unlinked bands just get you extra SDFPs, and most of the really good FPs are long gone to prebookings by that point.
6) Disney is losing money, as offsiters would be there without the throwaway, but people are being turned away from FW (and possible value resorts?) because of throwaways.
Since there is still availability at FW, I don't think this stands up well either. And I am sure some offsiters would not visit WDW unless they could get their throwaway benefits.
I have followed this discussion for days and a few times I have been lost on this point... How can unlinked (aka have no ticket attached) MBs be used for SDFPs? That makes no sense to me as whether its 60, 30, or SD, don't the MBs need active ticket media to be eligible for FP+?