Re: Most of the complaints about it...
"... are because those sysadmin need to learn something new and they really hate it, and fear it."
Sysadmins are paid to keep things working. They know through experience that changes break things. Therefore they realise that the only changes that should be made to something that works are those that are absolutely essential. This means that changes should be evolutionary not revolutionary. I've yet to hear about one essential thing that systemd's supposed to have fixed.
I think the resistance to learning something new is on the part of those coming from the Windows side being reluctant to learn how Unix works.
"They like a fossilized Unix that must not change since it was written on stones in 1970."
I can't claim to have used Unix back in 1970. However I have used it since the early '80s so when I tell you, as I do, that Unix has evolved greatly over that time and has not become fossilized I do so from long experience.
"My Linux sysadmin is a perfect example of them...."
Your Linux sysadmin appears to know what he's doing. You should learn from him.