It's not so much that as there is the net-negative side effect of having people redo the same work over and over again at their day job or whatever. It horrifies me when I think about the number of hours of people's lives wasted on things like that.

It applies to both sides of the argument, with organizations keeping things to themselves or others avoiding codebases for the inverse reason.

Absolutely. LLVM exists because GCC is GPL; that's a feature not a bug.