The idea of using EBIT (earnings before interest and taxes) is to nullify the effects of financial policy and tax rates when comparing different companies because they can vary widely from one company to the next. By ignoring interest (financial policy) and taxes, it allows an analyst/manager/bank/etc to focus on the company's ability to turn a profit from it's operations. It makes comparing different companies more "objective" in a sense. EBIT has its shortcomings since is does not nullify accounting policy (which is why EBITDA is used, although even that's not perfect).
Also there is a big misconception in one of your questions:
"After all a company could borrow massively and spike up it's revenue".
This is not true. The cash a company borrows does not affect their net income. To get technical, it is a balance sheet transaction. Borrowing cash only affects accounts on the balance sheet (namely cash and debt). Eventually the interest expense will flow through to the bottom line, but the cash itself has no effect on net income. Only sales will increase revenue.