From Wiki:
Operation
Reverse thrust is typically applied immediately after touchdown, often along with spoilers, to improve deceleration early in the landing roll when residual aerodynamic lift and high speed limit the effectiveness of the friction brakes located on the landing gear. Reverse thrust is always selected manually, either using levers attached to the thrust levers, or by moving the thrust levers into a reverse thrust ‘gate’. When thrust is reversed, passengers will hear a sudden increase in engine noise, particularly those seated just forward of the engines.
The early deceleration reverse thrust provides can reduce landing roll by a third or more. Regulations dictate, however, that a plane must be able to land on a runway without the use of thrust reversers in order to be certified to land there as part of scheduled airline service.
Once the aircraft’s speed has slowed, thrust reverse is deselected to prevent the reversed airflow from raising debris in front of the engine intakes where it can be ingested, causing foreign object damage. Thrust reverse is effective at any speed, and, in unusual circumstances, can be used all the way to a stop, or even to provide thrust to push the aircraft backward, though aircraft tugs or towbars are more commonly used for that purpose.
If the full power of reverse thrust is not desirable, thrust reverse can be operated with the throttles set at less than full power, even down to idle power, which reduces stress and wear on engine components. Reverse thrust is sometimes selected on idling engines to eliminate residual thrust, particularly in icy or slippery conditions, or where the engines’ blast could do damage.
Good post. As you stated, reverse thrust is most effective at higher speeds. Usually, you start reducing reverser use at 100 kts, with reversers stowed around 80 kts (94mph). In a two engine aircraft, you have to be very careful using reverse thrust with a reverser deactived as you may have control problems due to the asymetrical thrust, and limits on nose wheel steering to counteract the inevitable move towards the edge of the runway.
The problem here is that the pilot tried to land a somewhat heavy aircraft on a relativly short WET runway with no reverse thrust. Aircraft braking on a wet runway can be marginal due to hydroplaning, and with no reverse, you only have brakes to stop the aircraft. You can apply all the braking you want, but you are just along for the ride—a very uncomfortable feeling.