It’s mainly just that, since information can be copied without removing access to the original from the current possessor of that information, I don’t see a good justification to restrict use of it. If you steal something, the original owner loses while you benefit. Since the unexpected loss is probably felt worse, this is a net negative and therefore a bad thing. But, if you copy information (which IP by nature is), you can give it to an arbitrarily large number of people without even taking it from the original, enough benefit to in my opinion outweigh the frustration that loss of control causes. Capitalism adds another element given it also ties monopoly over a given bit of information to artist compensation, but even without capitalism, I don’t think information should be seen as property