Don’t get me wrong, I don’t think it’s the worst crime in the world to cheekily share an account. There’s no objective definition of what is a ‘fair’ way to charge for software like this, so it is tricky. I do think, though, that from Zwift’s perspective, it’s completely irrelevant that you’ve chosen to only buy one turbo to share between two people.
I think that the ‘fairest’ way would be to pay per km, but that wouldn’t work very well for a lot of people, and probably not well for Zwift either! At the end of the day, the sellers have to choose a payment model, and the buyers can choose whether to buy it or not.
In practice it would be a stretch for people on a forum sharing a subscription, but it’s fundamentally not so different. Why should Zwift care that you’ve married that person, share a house and turbo with them?
Personally I don’t get why they should offer a family discount – as a paying subscriber (which I’m not yet, as it happens!) I’d think it wasn’t very fair on me if someone else got their subscription cheaply (and therefore, by implication, my subscription was more than it otherwise would be) simply because they lived in the same house as another subscriber. But, you know, first world problems and all that.