I've seen the result of intellectual property theft and I don't like it. The market adjusts and less people spend time creating things that are easy to copy, so the quality of those things are diminished.
Can you demonstrate there would be a net loss for society? The burden of proof is on you.
An example that is at the top of my head is hard to call a net loss for society. But I can see how it could easily translate to other fields. And of course something like net loss to society would be extremely subjective, so proof is difficult. And it's probably impossible to measure.
The example would be PC video games. They were very good for a while and kept getting better. But as the internet grew, it became very easy to copy them and share the copies. Most major games released these days are ports of console games. Why? Producers make more money (if you look at the sales figures it's quite plain) on console games because it is more difficult to copy and share them. Of course it is possible, but much more difficult than a PC version. So we have these custom built PCs that absolutely destroy consoles as far as gaming power is concerned, but the only games that are released for PC are shitty ports of games that can run on the current consoles.
Video games may actually be harmful to society though. Perhaps PC games were better for society than console games because they pushed hardware developers to constantly upgrade their products., although they still do.