First it was "just an init to replace SysV", something I could get behind, and back in 2012 or so I was actually excited about it. Then it started growing, replacing individual components of GNU/Linux with a monolithic mega-app that has more in common with Windows NT based OSes than with anything UNIX-like. Gone is the philosophy of "do one thing and do it well", replaced with "do everything no matter the quality of the results".
I've always been a Slackware user since I started messing with Linux in the late 90s, and these days I find it getting faster and better while mainstream Linux distros slow down and grow more and more bugs. One of my benchmark systems for observing the growing bloat of modern OSes is an Atom based netbook from around 2010. It shipped with Windows 7 Starter, which it ran acceptably but not great.
Recently I tested Windows 10, Slackware 14.2, Ubuntu 14.04, Ubuntu 16.04, Debian unstable, OpenBSD, and Elementary OS Loki on it. Slackware was the fastest OS on it by a wide margin, followed by OpenBSD, then Debian, Ubuntu 14.04, Elementary, Windows, and Ubuntu 16.04 dead last. Guess which of those (not counting Windows) do not have systemd? Yep, Slackware and OpenBSD. Maybe it's a coincidence, but given how Ubuntu 16.04 on my modern workstation gets progressively slower with each systemd update, whereas Slackware on the same machine continues to chug along with no issues, that's telling.
All of that said, systemd was and maybe still is a good idea, if only they can stop trying to reinvent the wheel and instead fix the spokes they broke along the way. I can't say I'm happy about eroding the UNIX philosophy from Linux, but if systemd is the future of Linux then it damn well needs to be a stable future.