[rad_gruchalski]

To comply with the license, the Evil Corp would be required to share their modifications giving anybody who sees this as their market advantage the ability to do exactly the same thus diminishing the advantage. The Evil Corp would not be required to share the code which talks to the modified GPL'd library.

That's the spirit of this license and everything is working as intended.

But it's a good line of thought. Here's another thought experiment. When compiling say golang or Rust program, all dependencies end up being compiled into a single standalone binary. If a dependency of a dependency pulls in an unmodified GPL module, what impact does it have on our resulting binary? The common understanding is: if we're asked to share the code of the GPL dependency, we can share the original unmodified dependency and we're not required to share our code using the dependency.

Until we're proven otherwise, we should stick to that common understanding.