[Jasper_]

Well, traditional UNIX is also accessible over RPC usable by non-free software. They're just known as pipes.

Spawning processes and communicating over pipes is a UNIX tradition and also lets you sidestep the GPL. Should RMS be screaming about that too?

[anonbanker]

Did you really just compare systemd (giving non-free software a PID1 GPL backdoor) to Unix pipes?

Maybe you can explain what a "derivative work" means to you, in relation to the GPL?