Earlier quoted context omitted.
In my experience, they'll either be much more careful about hiding their reliance, or just strip Linux out of everything. Not contribute back.
And you think by not punishing such companies then they'll come in to compliance? It strikes me such companies never intended to comply with their legal obligations - make that position financially untenable and use the money to support development/developers who are compliant.
Most companies will see a lawsuit as an attack, and blacklist interacting with you in the future if they can. It reflects badly on the FOSS community, and makes future interactions even more difficult. There are a lot of businesses that will fight relying on any FOSS product, but leap at precisely the same thing with a paid license.
However, more polite requests usually get canned without reading.
This is a tough problem, with hypersensitive businesses thrown in the mix. Wielding the GPL like a hammer won't help, but ignoring it won't either.