That sounds like SaaS specifically. In any case, I agree with you, it sucks that you don't get to actually own a piece of software, even though I understand the benefit of a constant revenue stream for the developer so they can continue to push updates (and the second reason why they do it is probably preventing piracy, even though it's still a bit hit or miss - with Adobe CC it's still pretty easy, but Office now can't be cracked IIRC).
I think the best middle ground would be to do what Sketch does with their Mac app or what Photoshop used to do, where you pay a flat fee for the app in its current version, get a few free updates on top and then after some time have to pay again to upgrade to a newer version.
Well, technically, it is decent at being a currency even by your definition, just not in our society. I do think in something like a post apocalyptic world crypto would be a pretty good payment method, provided the technology worked to an extent where it would be possible to maintain.
I also refuse to believe it was invented to be speculative, I think it was basically a thought exercise to see if you could make a digital currency in a world where you can't trust anyone.
Though the fact that right now it's an unregulated currency that can be exchanged for regulated currency does allow for some pretty spectacular scams.