What century are these guys in?
"In the *nix world, autoupdate technologies aren't widely used,"
Maybe 30 years ago ( BSD, tapes, and 64kb Internet access), or even Linux 20 years ago. However a quick look at some old Linux admin manuals shows that by 2001 SuSE shipped with on-line-update as standard. The defaults were to run weekly and apply security patches. I cannot believe that most other *nix systems did not have their equivalents.
In that time the only update relate problems that I can recall were a Postfix configuration backed up and replaced with an updated default (spotted and fixed within the hour), and a few occasions where users had "cut and pasted" dodgy PHP that stopped working after an update.
It's really not hard to keep a Linux server tolerably secure. With any decent distribution that is the default, and it does not have a significant cost. You have to decide to do something (stupid) to introduce a meaningful insecurity.