The problem is when you fork your own distro you quickly discover that using systemd is the easiest way to maintain it. It isn't a coincidence that medium and small distros like Arch Linux picked it up in addition to the big boys. Unit-files save package maintainers boatloads of time they used to spend having to writing and maintaining initscripts a lot of which is copypasta boilerplate anyway but its usually distro specific copypasta.
This is the source of a lot of the strife in my opinion. The people who actually do work to maintain distros like systemd, the users not so much.
My apologies. The wiki article linked provides a decent primer (it also lists relevant specifications).
The gay marraige issue isn't a States rights issue no matter how much supporters wish it was. The federal government doesn't issue or dissolve marriage licenses it is completely the domain of the States. All the Federal courts have said is that if the states wish to have a legal institution of marriage that it must be compatible with the 14th amendment, and States which do not allow gays to marry do not meet that requirement.
The federal courts are not infringing on states rights, they are protecting individual rights granted by the U.S. Constitution from infringement by the States.