What resources are they using, though? Marginal cost of copying the code is close enough to zero to practically be zero. The project consumes the same amount of resources regardless of whether or not any one user decides to use the software. In other words, where's the "load" in freeload when someone uses open source software under the terms of its license?
It's more of a moral argument. We want open source available for people to use for small projects, but once large organizations take our software and make billions of dollars on top of our architectures without contributing back to the 5 people who made that possible, it's disingenuous.
My general rule of thumb is: if you are a large organization using community powered open source software, you should be paying individual project communities 3-5 senior engineer salaries per year. If an open source project has 5 million users, the creators shouldn't be sitting around worried about making ends meet. This isn't about token gifts of $10k or $50k per year in "community sponsorship." It's about sustaining and growing projects big companies rely on to function in the first place.
The resource is the time and expertise of the people contributing to the projects.
If someone only ever pulls code from open source repositories, and never contributes (either with money, code, time, etc) then I think the 'freeloader' label is valid.
Someone using the "cost of copying the code" argument has nothing worthwhile to say, as they haven't actually thought about what goes into the code. Here's a hint: The GitHub fairy didn't magically add that code to the repo.
Trying to guilt-trip people into paying your absolute costs after you've already given them everything for free is a losing strategy. You either need to charge for complements yourself (support, dual licensing, something) or you need to get money-hatted by someone else who can do those things, like Red Hat.
