While the "abandoned property" rule might apply to title, I think it is stretch to think that it applies to activation for service. True, the "abandonded" HR20 may now "belong" to you, and you can do whatever you want with it, DirecTV is under no obligation to activate it for anyone. The act of abandoning it says that they have declared the unit to be at "end of life" and of no significant value. What units they activate is, and always has been, a matter of their discretion. They could even refuse to activate receivers that have always been "owned" if they change hands. That they do activate them is a good thing, but I don't see any contractual obligation or implied warranty on their part to do so. When you purchase a "non-leased" device DirecTV is not a party to the transaction, and so there is no guarantee, express or implied, that is conveyed along with the device.
If the HR20 is end of life, why did D* recently give it a software update? If it has no significant value, why can people sell it for $100?
The reason they don't want to activate previously leased units is for profit only. Not that that's a bad thing, as they are a for profit company, but let's not sugarcoat it.
D* doesn't want ANY owned units period. It wants to take the depreciation of its leased units as a tax write off. The more owned units there are out there, the less leased units there must be.
However, it's illegal to not provide an option to buy a box. So D* offers an outrageous price to buy the box, coupled with the policy of activating as few of them as it possibly can, and also by charging an additional service fee for each owned box that just so happens to match the lease fee. FYI, most of this behavior is illegal for cable providers, but the FCC has temporarily waived enforcement of these laws for DBS systems for now.
I totally agree that abandoned property laws does NOT apply to the service -- the previous service was cancelled and no longer exists. However, D* is dangerously flirting with the FCC. They have to be careful not to make them angry.