This isn't true, I don't think. For example, Instagram was built on Django, but I don't believe the Django founders magically got money because their totally free to use OSS was used in the way it was licenced.

If you don't want people to use your software and make money, then don't release it with a licence that explicitly says you may make money from this software.

What was stolen?

There used to be a social contract that you got free code if you behaved nicely with it. Then companies realised social contracts were worthless (not just in open source) and stopped following them and only followed legal contracts.