Rental car companies have a vested interest in credit card users. After all, the companies need to get paid by consumers and the days of cash deposits are long gone. Debit cards are also viewed as undesirable by the rental car companies as a proxy for "non-creditworthy renter" (whether fair or unfair). Using debit cards frequently come with many restrictions, if the rental car company will even accept the debit card at all! Without multiple forms of identification, large security deposits, and a successful credit check (among other provisions), the car renter with a debit card will likely be taking a taxi or Uber instead.