Yeah a place I worked for had managers that thought that way. Then something broke and since the guy who knew how to fix it was fired a long time ago... well... I was already long gone by then. But their system was down for nearly a week.

Now if the managers established any kind of process then personality conflicts wouldn't be an issue, everything would be documented in advance (ie. planning) and the IT would just be following an agreed upon plan. Both management and the staff know everything that's happening and why it's happening. And if there's staff turnover it's no biggie because everything is documented and the management knows where the documentation is.

But that requires work... by management. So in many places it doesn't happen.

The reason why you have arrogant IT staff is only because they know that you don't know how anything works and they do. They know that if you fire them you'll be fucking over yourself because if something breaks there's a good chance you won't know how to fix it and it may take their replacement a long time to figure it out because you never gave the IT staff an adequate amount of time to document anything.

Sure when you fire these guys things won't break immediately. It might be a year, even several years before that critical thing (that you never required to be documented, no time for that) breaks and the system is down for an extended period of time.

The IT guys are arrogant because their boss is too stupid to know how to manage things properly to know how things are set up. Some managers are too stupid to even know why their IT guys are arrogant. They're arrogant because they know that by firing them, the manager is fucking himself over. They're just underestimating how stupid their manager is.

If you feel attacked by this, you’re one of the idiot IT managers.