Well a banana is a thing. You can have ten bananas in stock. You don't have ten softwares in stock. Unless you put it on a carrier and sell it one at a time, like a painting. Software is quite unique when you go the subscription route. What is it you're buying, really? You're buying human labor that was automated, so you don't pay for the labor, but for not having to hire someone. That makes it so unique...
I'm still paying for the product, not for the invention of the concept of the product.
Matching different payment models is pretty common in business, not some weird thing that only applies to software. A buffet takes a fixed price per customer, and tries to match it to the actual amount of food the average customer eats. A bank (at least in pre-fiat currency) takes money for short unpredictable periods of time and lends it out for long fixed periods. A hotel takes a variable price per night and matches it to their fixed cost of rent, maintenance and cleaning. An ISP takes a fixed monthly fee, and tries to match it to how much data transfer the customer causes and where the data is flowing. An airline takes a variable price per customer and matches it to their largely-fixed cost of flying the plane. And these new-age software companies take a fixed monthly fee per user and match it to a one-time development cost.
