Not letting people do their jobs, or in how fast they can do their job. Employees are a captive audience, and if there was competition they would probably chose something else.
I tend to summarize my experience with IT in large companies and universities like this: IT is evaluated in "how secure things are", or "whether things are not broken". The only sure-fire way to ensure a system is secure and not broken is to make it completely unusable, so that people don't use it. If people don't use a system, they can't break it!
Never mind that it took double as long, and sucked the life out of everyone subjected to the system.
Efficiency!
Now what.
There is also an inversion of responsibility here. It really should be IT's job to 'adapt the tool to the process' instead of externalizing it to their staff. Until they can do it, the staff needs outweigh the lazy 'default no' of IT.