As a user of linux on the desktop, I've never felt a moment of concern over the fact that it takes longer to boot than did Windows. I'm not sure who is panicked by this and I'm distressed that we would solve all of our problems with init by embracing systemd.
I wonder why booting a computer may be a concern for a desktop user at all. With hibernation being polished enough (on Linux and elsewhere), one mostly puts a computer to sleep, then continues exactly where left.
Boot times may be important for cloud instances, though; the faster you can spawn more nodes to accommodate a load spike, the better. But cloud instances are usually pretty stripped-down, and often get spawned form pre-configured images where much of the discoverable stuff is hardcoded.
My rMBP is the first device that I have used yet that I feel boots quickly enough. I mean, it's a few seconds. And that's on top of the fact that I rarely actually turn it off. SSDs are really necessary to have tolerable boot times.
As another user of computers, it's pouring if I have to boot up more than one or two groups of things a week. If it ever takes more than 3 minutes, there's something wrong with the hardware.
If Gnome requires systemd, lets drop Gnome.