Again. Let me help you. A TEMPLE was a BANK. That’s why.
Don’t be daft. Moneychanging (converting between currencies, storing money, lending money at interest), was a terribly important function given the diversity of monies used – today that function is provided by central banks and larger commercial banks, and travel currency exchanges. In the ancient world the roman treasury used ‘agents’ the way we use these banks. (I prefer the agents model and want to eliminate consumer banks as they are known today.) The problem was that the people at some temples took abusive advantage of the poor. When Romans invaded Judea they established their temples and their money changers. This competition prevented the Jewish priests from charging high rates at their temples. And so they sought marginal cases to charge usurious rates. This is what jesus was rebelling against: the abuse of the poor. The complete story is never stated. The fact that Jews specialize in usurious lending to those who cannot afford, or lend into moral hazard, predates their introduction to europe – it is the original occupation of their priesthood.