In the middle of Everybody hates Firefox updates is the following (about Firefox updates specifically):

Only after I heard from dozens of different users that the rapid release process had ruined Firefox did I finally get it through my thick skull: releasing an update is practically an act of aggression against your users. The developer perspective is "You guys are going to love this new update we've been working on!" The user perspective is "Oh god here comes another update, is there any way I can postpone the agony for a few more days?"

Yes. This. Change 'users' to 'sysadmins' and apply it to all software and you have a good snapshot of the sysadmin reaction to updates. There are pragmatic reasons for this but most sysadmins haven't deeply considered them; we just know that we don't like them. Well, we usually don't like them in practice.

What it generally comes down to is that except in rare cases, our systems are working right now. When you have a system that works now, an update is normally not a huge improvement; you have a working system now and hopefully you'll have a working system afterwards too. So most updates are a kind of make-work where you take a bunch of time and effort to wind up where you started (with the chance of winding up worse off). This is not exactly a compelling pitch.

(In theory, there are certain sorts of updates that we should like, things like updates that only fix bugs and improve performance. Sadly such updates basically don't exist in the real world; even when people try to create them, the possibility of mistakes in the update means that sysadmins have to test and qualify it.)