Religious sentiments aside, systemd scratches a number of itches that eventually needed to be addressed. The main one is parallel startup of daemons. On a SSD based machine (and note, these are anecdotal runs), CentOS 6.5 takes about a minute to fully boot to a login prompt. On CentOS 7.0 with systemd starting anything that isn't relying on another process at the same time, well under ten seconds. Similar with a shutdown.
The second item is being able to place processes in containers and set limits before they start. This can be done with SVR4 startup with wrapper scripts, but systemd makes it easier.
The main thing I see against systemd is that it is new. I remember pushback in the early 1990s when Linux distros went to the SVR4 way of starting up from having everything in a big /etc/rc file with branches to other /etc/rc.whatever files, and finally a rc.local file.
The second downside is that systemd has more moving parts. However, it will only be a matter of time before the bugs get eradicated. Heck, sendmail used to be the hair-puller for sysadmins and even that beast is now a long since solved problem.
If one wants to gripe about something, gripe about firewallD. For bringing Windows type abstraction to Linux, it is great. Anything else, it is just another questionable layer that is of dubious value at best, a potential vulnerability at worst.