The problem of IT winning arguments
Yesterday I wrote about how sysadmins are overhead. One of the consequences of this is that IT does not actually have real power. The real power accrues to the people who are doing the organization's work, whereas IT is just keeping the machines dust-free.
Remembering this will make life less explosive, because the people with actual power can usually squash IT flat in thirty seconds if push comes to shove. Generally you don't want it to go that far.
(This is part of the core of the problem with punishing people at universities. Tenured professors are not only tenured, they're what the university is about.)
Where IT manages to successfully call the shots over the objections of people actually doing stuff, it does so through what is ultimately fear, usually fear of security problems or fear of expense. The problem with this is that people resent being scared (or equivalently, held to ransom), even if you are correct.
And this assumes that you've actually scared the people. Often, IT has only scared management, not the actual people that their policies affect. (This is always the case if IT's argument is 'the other way costs too much money', since that's a management concern.)
(The other problem is that people don't stay scared, so IT has to try to re-scare them every so often.)
The best way for IT to sell things is to find some way that they make life better and more convenient for people. 'Do this because there is no viable alternative' is a poor second.
Sidebar: the problem of money scares
Fear of spending money is an especially pernicious approach for another reason; it's often very difficult to quantify the benefits of spending the extra money, and thus difficult to defend doing so. It's easy to produce figures for how much management could save by locking down worker desktops (you just show how much time support staff would save and how much that time nominally costs), but much harder to put a clear dollar figure on not doing so, and thus you wind up with the virtual furniture police.