I can see both sides of this...
1. If I buy a product, bring it home, and find out that it doesn't work as expected, I can return it. Sometimes for cash, sometimes for store credit, sometimes for a different model.
2. But we're not talking about a CD player, where I can bring it back to you and you know that I have in fact returned it. We're talking about a piece of software (the RRG file) that is easily copied as many times as I see fit. So who's to say that I've REALLY returned it. How can I prove that I haven't made any copies? Even though I may only want an older version, there's no way to prove that what I didn't end up with was a copy of both. Of course why I would want to do that (or why Stacy would) is beyond me, but, there you have it.
The solution to me would seem to be that each version of MJ should accept a license from any newer version. If a person wants to upgrade, they still have to pay, but if they buy a current license, they can then use whatever earlier version they want. After all, it's pretty safe to say that once 8 is officially released, 7 will cease to generate any revenue for JRiver, so it's not like they would lose any money by allowing this.
Of course that doesn't help anything NOW. All of the previous versions are done. And unless JRiver wants to go ahead and start retrofitting all of the old versions of MJ to do this, then there's really nothing that can be done. It could be something to do in the future though.