> For me, Linux is about control.
And exactly what aspect of control is taken from you by systemd?
> Apparently, systemd replaces all that and more with a single monolithic
> structure, which seems more akin to the Windows way of doing things.
No it isn't. Lots of commercial unix like operating systems had moved on to some form of init system not based on shell scripts f.e. Solaris, Mac OS X etc.
> It's main selling point appears to be boot-up speed
No it isn't.
> IMO the cost that we must all pay for that extra speed is just too high
And what is the cost exactly? What exactly do you have against systemd? Only thing you stated is that it is monolithic and non unix way. I don't rally care about it. What practical limitation does it cause? Only valid complains about systemd I've read so far is that is not standard as it is an implementation and in theory this shouldn't be done like that. And I agree but still it exist, it works and it is not going anywhere. The second complaint is that it uses binary log file. It does in fact but I also don't care about that. I can config it to forward to syslog so it is no problem. Actually by using such architecture it can start logging earlier than sysvinit system which is better. These two flaws do exist but they do not rule against systemd in general. It is still a step forward in right dimension.
Look at CoreOS and its components like fleet - this is what systemd was designed for and it is strictly server operating system.