> Notable counterxamples (excluding e.g. Linux)

These are mostly executables/end products, aren't they?

GPL allows protecting the business logic by discouraging hostile forks: after all, forks of such projects can't relicense GPL files w/o permission, and upstream can just copy the changes back w/o having to ask.

On the other hand, permissive license favor dissemination. Would {fmt} (libfmt) be as ubiquitous as it is, if it were GPL instead of MIT?