Interest is what you pay the person you borrow the money from for the risk they are taking that they will never get their money back.
Business loans have nothing to do with consumption. They have to do with a business man coming up with a business plan that generates enough revenue to cover his expenses, service the interest on the loan, and have enough left over to generate a profit for him.
Is it immoral to charge a business interest, when the business would not be able to get started without a loan, even though it would be able to pay the interest and the principle in a couple of years?
Everything in business has to do with consumption.