My point exactly (notice I didn't say MS distributes bash - it doesn't, as you pointed out).
Bash being GPL doesn't stop MS from benefiting from it by providing it to WSL users which make WSL more valuable for them. It also (as we talked in the other comment) doesn't prevent Amazon from running a database and charging people for it.
So what's this great advantage of GPL that it would make it worthwhile to keep the entire copyright system just so we could still have GPL?
If you dig around in its origin, GPL was concieved as a tool to "fight system from within system". If there's no system, you don't have to fight the system.