Some designers (e.g. Henri Mignet's Flying Fleas) want to build the simplest possible airframe. Simple reduces cost and time of construction. Simple also means fewer controls for a student pilot to learn.My answer is no, not really. Perhaps the question is why would an aircraft want to have no direct means of roll attitude control? I trained as a flying qualities engineer and can't see any reason why a designer would willingly give up the best roll control device we have invented in favour of using the secondary effect of the yaw control!! Although an ultralight might want to save weight, giving up the ability to operate in anything other than pretty calm conditions is a compromise too far for me. Birds just use a different systems, many have swing wings or can vary wing area - we don't have a weight efficient means to do that!! Increasing dihedral angle will make the aircraft want to fly in a straight line, requiring a more and more aggressive yaw to roll the aircraft (or larger and larger ailerons or slower roll rates). Properly designed ailerons just makes any aeroplane much more enjoyable to fly... Why else do we fly recreational aircraft?
As others have pointed out, as long as you keep wing-loading light and landing speeds slow (e.g. SkyPup), cross-wind landings can easily be converted into diagonal landing on existing grass runways.