Ben, you're really just being a child here. Is that a really big problem to add a small text file to your package?! Is that a big maintaining burden?
If you can't test it, systemd team can, just like there are arch teams to test packages on other archs the maintainers can't. It's not something that changes code or functionality to that level that it can't be maintained with help.
Nobody is forcing you to use systemd, there are just people how are asking to let them use it.
You talk a lot about Gentoo is about choice, but you are not giving that choice. You're forcing people to *not* use systemd (not using something else), because you don't like it. Plain simple.