Then they would probably be able to make more money selling subscriptions than other developers that are less known. I don't know how different that would be though from if they sold physical products. One important thing here is that there is a limit to how many subscriptions one developer can sell. This is done to emulate physical products as much as possible.
Also, they would probably sell the subscriptions for a higher price than other developers, since they can, which would mean that people who don't know about that person would buy from someone who is cheaper.
> Why not opt for the Spotify model? Usage = money. Why turn this into a popularity contest?
That means there has to be usage statistics collection in all software. Since the software has to be open source, that could be abused a lot, including removed. I also don't like the idea of having any requirement like that on the software. It would for example require that the software has access to the internet which doesn't work well for some software.