What about Dutch hire bikes with rear drum brakes only that are actuated when you force the cranks backwards? How do they compare?
Sheldon Brown on Coaster brakes (his emphasis at the end)
Pro:
Coaster brakes work just as well in the rain as they do in dry conditions
Coaster brakes generally require less maintenance than any other type of brake.
There are no cables running from the handlebars, giving a tidy and simple appearance.
The lack of cables with a single-speed or kickback two-speed coaster brake is particularly advantageous for folding or take-apart bikes.
Coaster brakes can be a good choice for handicapped riders who lack sufficient hand strength, or for arm amputees.
Coaster brakes are usually quite narrow, fit in
110-114 mm spacing, though they can be fitted to frames with wider
spacing by adding washers along the axle.
An internal-gear hub can include a coaster brake, providing both gearing and rear-wheel braking.
A bicycle with a coaster brake can coast backward with stationary cranks (useful in acrobatic cycling).
Con:
Coaster brakes make it awkward to get started, and prevent the use of clip-in pedals or toe clips and straps, since there's no easy way to rotate the pedals to starting position.
Coaster brakes often cause skidding, resulting in excessive tire wear.
When coaster brakes fail (usually the result of chain breakage or derailment) they fail suddenly and completely.
Coaster brakes are prone to overheating and fading when used in mountainous areas.
A coaster brake inside an internal-gear hub complicates the mechanism and reduces the options for lubrication.
A coaster brake is not compatible with derailer gearing or a
chain tensioner.
Too many bikes are equipped with
only a coaster brake, so there's no back-up system in the event of brake failure.
To be safe, any bicycle needs a front handbrake and some sort of rear-wheel braking system. This could be a handbrake, coaster brake or fixed gear.