On planes like the Hot Stik, the flaps are not needed for landing. They are intended to be used to expand the performance envelope of the plane. You have the option of coupling the flaps with the elevator ala control line stunters for super tight loops or for slowing down to almost a hover. You also have the option of using crow to really put the brakes on the plane as you dive almost vertically to a landing.
Like the CD player in your car, they are an option, not a necessity. People who spend the whole flight boring holes in the sky at full throttle will never miss the flaps.

Competition fun fly airplanes frequntly use coupled flaps. They don't need them to be good sport planes, they need them to be competetive in a fun fly contest.