That’s an old trope, but it’s not really true. My TV has a user guide, so does my fridge, my brush cutter and my soldering iron. And, while I wouldn’t say that “hooked” is a term used widely across the whole software industry - though obviously in this context it’s more common - nevertheless, it’s hardly a term we share exclusively with drug consumption.
In fact, without thinking about it much, I think the nearest similar industry may possibly be day-time TV.
Hook/hooked aren't limited to drugs and software. Books, shows, songs, news articles, etc. all have hooks. They just don't use the term user because the mode of interaction is different.
This is not true for every industry. For example, a lot of mobile games are "freemium".
It might be worth offering free services to some people, in order to get them hooked. Maybe that way more end up signing up.