The fact that it did many things easily and correctly that init/cron/monit only did after navigating a minefield of gotchas, reinventing the wheel, and employing obnoxious hacks to do things that ought to be simple (parallel init). Init scripts are easier to tweak, no doubt about it, but I'm equally sure that if I was actually throwing together a distro I would want a modern init system.

Also, remember that launchd on OSX has been around for a decade. People from the linux world who encountered it tended to think "hey, this is kinda nice, I wish we had something like it." Perhaps launchd itself had a predecessor somewhere, I dunno. But the point is that people had seen these systems in the wild, so when someone showed up who was serious about seeing the project through there were a bunch of maintainers whose reaction was "about damn time" rather than "what is this?"

One major thing that we get from systemd is cgroup management, that gives resource and namespace management at a per process level. This has actually been in the kernel since 2008 but to use it you had to have some really bad ass programmers to give you an access interface to the features. It's now trivial to run a hosting server where each site has a set amount of cpu and ram without the virtualization overhead. Before that the option was openvz and before the option was virtualization.

There is a very loud minority in the linux community that doesn't want things to change. There are a ton of linux users who's lives this improves, and they are not as noisy.

Debian is the larges distro and when the maintainers took a vote systemd won with like a 60+% majority. Almost all other distros that are going to, have switched over the last 3 years.

Personal opinions from the user perspective aside, it's significantly easier to maintain from a distribution / package maintainer perspective, so it's unsurprising they'd want to switch.

Just this periodic strange urge to adopt superior technology that fixes several broken things at once, instead of keep going with what you're familiar with and sorta-works for decades...

1/ Maintaining init scripts is a significant part of the work to be done in a distribution, and systemd makes this task easier.

2/ Gnome started requiring systemd (via the dependency of GDM on logind). So, if they want to keep supporting Gnome, they have a choice between switching to systemd or developping some shims. And it's probably safe to assume other major pieces of software (KDE?) will adopt similar requirements.

I think that force is just the developers and maintainers of distros and upstream projects.

Code contributions, even if controversial, pack a much stronger punch than emails, forum posts, blog posts, etc.