> Just because the marginal cost of something is low/zero doesn't mean companies shouldn't charge for it.
It definitely should. That's why some of the money collected beyond the "marginal cost" is invested in R&D (capitalism 101). Of course entire industries (health, IT, concrete..) have been used to living off siphoning public money from corrupt officials as grants and partnerships for R&D so they don't have to worry about anything but maximizing profits for their shareholders. But where is that model taking us?
> Should an indie software developer using a freemium model be crucified because the binary they ship already contains the code for full functionality?
Sure. Why is freemium even a thing? Would you imagine a music CD where a paid unique key is required to decrypt the 5 last tracks? Or a restaurant toilet where the toilet is free but you need 2$ more for toilet paper?!
In principle, everything should be free for everyone because everything belongs to everyone. But even if you don't agree with this principle (why?), freemium is a fucked up model that only incentivizes producers fucking over users some way or another.
> Economic rents are a very specific phenomenon and it simply does not mean charging for something that is perceived as being low/no effort.
As an anarchist, i understand "rent" to be artificial value derived from "private property". Private property by definition is just a religious belief (materialized on a piece of paper, and guarded by the holy crusaders of the police), and does not involve efforts.
The efforts to conceive and build the product (whether it's a CPU or a house) were provided beforehand, and by a different group of people than those reaping the benefits of this "rent". That's precisely why "property is theft": it creates debt from the users of a resource, to people who did not work to produce it (if there was any work involved at all, which may not be the case eg. for land ownership).