They can still be disgusted at how people are building lazy derivatives

If you're disgusted at the prospect of people you don't like using and extending your code, then open source is not for you.

Did I write "I don't like"? The "lazy" is the problem, but then yes, I'm free to think that I don't want specific people to use stuff that required effort from my side (see the classic discussion of OSS being user by corporations without giving back anything, I can understand those that feel resentment).