They're fixing things that aren't obviously broken and have served us well for many, many years. That alone is enough to make me sit up and take notice. But in several cases they've then created issues this way.

It's purportedly a replacement for Sysvinit/upstart. There's massive scope creep going on. Among a zillion other things, it now includes its own DHCP server.

It's generally looked down upon to scrap an entire codebase because "eh, it's old legacy code, we can do better". And systemd is running into a lot of issues that demonstrate why that's a rule of thumb.