I disagree on the "full-throttle" part. That's be fine on consumer desktops. But Linux is mostly about production servers. Yes, yes... I know... mainstream Linux on the desktop is "just around the corner" and all that.
The question here is: What's with serverhosts these days? They are either embeded/integrated or virtualised. No one screws around (literally) with hardware anymore - not in a time where soc pcs cost less than 10$ a pop. So there is no need to fumble with init on that level. I haven't touched init or even runlevels for just about 10 years now - and I do lots of server stuff.
These days im running all my services in VirtualBox and copy, booting and ditching entire VMs at my whim. Fiddling with init would be a waste of time.
If you have a stripped down serverconfig that you have to distribute and scale, I doubt systemd will seriously get in your way. Yes, you have to hook your init stuff somewhere and yes you'll have to read about how systemd does things at this level, but on a dedicated server that might aswell happen in userspace or somewhere late in systemd boot. I'm sure systemd offers hooks for quick late-boot custom fiddling of some sort.
If finally all the Linux proggers get on the same page I'm all for it. If that page happes to be systemd, so be it. Simply the benefits of all getting behind systemd will move Linux forward faster than ever - that's my newest prediction anyway.