What difference does it make? In a competitive money market, negative rate loans will appear. Lenders still make a spread. The issue is not positive or negative

What difference does it make? In a competitive money market, negative rate loans will appear. Lenders still make a spread. The issue is not positive or negative rates, but whether the price expectation is stable or unstable. As long as the absolute value of price change is small the price is stable. As for why central banks prefer positive rather than negative, that's the better question.