Why would any company purchase a floor

Why would any company purchase a floor, since it keeps its interest payments up when interest rates fall?

While borrowers do not purchase floors by themselves for this reason, they do purchase them along with caps to create collars. Since the insurer benefits from a floor, it is willing to sell a collar for a lower premium than just a cap alone. The borrower gets the protection of the cap at a lower price than by simply purchasing the cap alone.