I believe GPL enforcement in general, and specifically around the Linux kernel, is a good thing. Because of this, I am one of the Linux copyright holders who has signed an agreement for the Software Freedom Conservancy to enforce the GPL on my behalf. I’m also a financial supporter of Conservancy.
That I hold any copyright at all to the work I’ve done is actually somewhat surprising. Usually one of the documents you sign when beginning employment at a company is agreeing that the company has ownership of work you do for them, and even things you create off-hours. Fair enough. But, my current employer does not do this. Its agreement lets its employees retain individual copyright to their work for open source development projects. I haven’t checked, but I suspect the agreement I signed with my less-steeped-in-F/OSS previous employers did not.
It’s something to ask about when considering accepting a new position.
I consider myself an idealist, but not a zealot. For projects I’ve started, I’ve used MIT, AGPLv3, MPLv2, GPLv2, GPLv3, LGPLv2, and Apache 2.0 licenses, based on the individual circumstances.
I believe if you’re going to build upon someone else’s work, it’s only fair to honor the rules they have set — the license — that allow it. Everyone isn’t doing that now with Linux, and are using the ambiguity over what is a “derived work” as a fig leaf. Enforcing the GPL is the only way to ensure the intent of the license is honored. We’ll also hopefully eventually gain some clarity on exactly what constitutes a derived work from the courts.