alt Hacker NewsThis is betraying a way of thinking that suggests what's normal now is the way it's always been.
Given "there was a time that subscriptions for software were virtually unheard of", it's safe to assume we're talking about more than a couple of years ago. To talk as if most users always used to upgrade, suggests you might be young enough not to remember the software industry before a decade or two ago.
In general, users very much didn't upgrade. That's exactly why the industry forced subscriptions on us. They weren't getting income anymore, when the older version of their software did the job perfectly well.
I'm old enough to remember that time. People did up grade. Some of them rushed out to buy the latest version when it was released. Some of them waited until they got a new computer. Many of them tried to not upgrade until someone using the new version sent them a file and then they couldn't open it thus forcing an upgrade. A few only upgraded every other version.
I wasn't an automatic everybody upgraded on day one like subscriptions are, but it amounted to similar: regular upgrades over time.