Violating the terms of a copyright license by making an unauthorized copy is not the same thing as theft. If I steal your car, I have one car and you have none; if I copy your data, I have a copy of your data and so do you. You have not been deprived of property, so there is no theft.
If you offer to sell me a copy of your data for $X, but I decline, then choose to get a copy of the same data from someone else for free, I have stolen nothing, since you still have your data. What you have lost is the opportunity to offer me a lower price, which I might have accepted. This is not the same as theft, and I am far less sympathetic to this vaporous loss of potential than I would be to an actual loss of goods or services.
As far as your belief that intellectual property can be extremely valuable, or that people involved in the development of new technology necessarily depend on it for a living, that is commonly claimed but does not correlate well with my experience. My career only took off when I started giving my software away - I made more money selling my consulting services than I ever did by selling licenses for my software, and freeware gave me a better reputation than shareware ever had.
Conversely, for a stretch of about five years not one line of code I wrote actually shipped, because the companies that owned the rights to my code changed strategy, went out of business, or simply lost interest in the project. I have heard similar stories from other developers. Think of all that work gone completely to waste, because it was all locked up behind a wall of "intellectual property!"
As far as software patents go, they have only negative value: they are worse than a zero-sum game. Patenting a software idea is a great way to make sure no software developer will ever read about it, since nobody wants to be liable for triple damages due to willful infringement. The only value a software patent has to anyone is the opportunity to sue a large corporation.
In summary, I don't agree that intellectual property necessarily has significant value, and I don't agree that violating pointlessly restrictive copyright licenses is necessarily harmful. Nor, for that matter, do I think "strong anarchistic elements" are a bad thing.
The justification is that making it easier for people to get what they want is generally a good thing. Violating the artificial gatekeeping privileges of an arbitrary rightsholder in order to increase the general happiness sounds like it is probably a good thing most of the time.