The biggest tension between software and one-off purchases is related to bugfixing, and especially security. It makes sense that you don't expect new features for a product that you paid for once. But, what is the case with bugs? If the product mostly does what it promised to do, but sometimes crashes, do you expect those crashes to be fixed for your version, or not? What it you're using a 10-year old version and a new critical (say, unauthenticated remote execution) vulnerability is found in it? Do you expect to get it resolved as part of the price you originally paid, or would you be ok with being told you have to buy a new version if you want this ?
How do manufacturers of physical products handle defects? Aren't they obligated to correct defects through recalls and similar mechanisms? I don't see why software wouldn't work similarly.
A good chunk of the software on my device doesn't need to access the internet, another big chunk does so using standard mechanisms (i.e. libcurl) that could be security patched out of band by the OS.
The only reason I routinely need to update most software, is that Apple/Google keep changing device screen resolutions/cutouts and they keep killing off old APIs
There's some merit to your arguments, but not enough to justify a subscription:
- Subscriptions are marketed as being a lot more than just bugfixes - new features being the big one. But there's usually no cheaper "bugfix-only" subscription, which means that someone who doesn't care about new features has to pay for them anyway.
- To be honest - yes, I do expect bugfixes for free if I've paid to buy the product. After all, a bug is a defect, and products are usually sold with the expectation that they will be fit for purpose. That's the principle which applies to physical consumer products, so why should it be any different for software? If I bought software that calculates my taxes for me, and it turns out a bug means that it applies the wrong tax rules, then I haven't got what I paid for. Why am I expected to pay every month just to make my software do what it was supposed to do in the first place?
- The developer is still incentivised to fix bugs in order to attract new purchasers.
- Subscriptions aren't a magic solution financially anyway, because there's an average limit to how long a customer stays subscribed for.