It's even simpler than that.
IT was developed as an outgrowth of the Accounting department. It's purpose was, and is, to support the company in doing business. Nothing more, nothing less. The better the IT department, the more profitable the company, mostly because they make it more efficient and reduce operating costs. The IT guys need to remember why they are there, who signs their paychecks, and who pays for all the neat toys they get to play with. In spite of appearances, IT is not at war with the rest of the company. You're all on the same team. If the company fails, you're ALL in the unemployment line.