I'm quite alright with that can of worms being opened for software. Enthused, even.

Copyright law has been playing semantic games with "buy" and "own" for decades. When I buy(1) something, it's mine, and I can do what I want with it. The person whom I buy it from doesn't have the right to rescind my rights over the thing I bought. When I buy(2) a software license, does the seller have the right to claw back the license? If not, then buy(1) and buy(2) are conceptually identical, and there's no difference between buying a license and buying the (copy of the) software. If yes or unknown, then buying(2) is not buying(1), as it does not grant ownership, but something else; not even over the license.

So what kind of transaction is buying(2) something? What do you get in exchange for money? It's clearly not a good, so is it a service? Is continued permission to use the software a service? Then if that service is interrupted the consumer should be entitled to some kind of reimbursement from the provider, right? Because otherwise the provider has an incentive to stop the service.

And if that one-time purchased software stops working at an arbitrary date, it should be subject to the same rules. Especially online software or software requiring servers to run.

You can still offer limited-time subscriptions, of course, and you can extend the minimum deadline for your server-dependent software to free as often as you want, just make sure people know what the deal is when they buy your software.

DVDs and other media also aren't yours to buy, they're just licenses and a physical container to use that license. You can buy software the same way you can buy a DVD, and you can rent software the same way you can rent a movie on a digital storefront.

I'm reasonably certain when I ordered linux CDs in the 90s, no one put a limit on the time frame I could be using them