On the other hand, there are some who, when traveling to Placencia -- or to Chicago or Sacramento -- would rather rent a car rather than wait for a bus, even though the bus is much cheaper.
It all comes down to personal preference and personal economics and, also, as Elbert said, to where you are staying on North Ambergris. If you're staying at, say, Grand Caribe or points south, that would be a different issue than if you're staying at Mata Chica or Portofino or points north.
People with handicaps or physical limitations also may have trouble with some water taxis and docks.