The forward facing hackle does move enticingly, but realistically, a regular, backward facing hackle moves enticingly as well. The forward facing hackle opens up more, and the backward facing hackle closes down more, but they both move.

I believe the answer to the forward facing hackle question is to not look at the flies in isolation. Look at them as part of a system, with the rod and the line as integral parts of the system. The beauty of tenkara is that the long rod and light line helps to keep the line off the water's surface, which results in less drag and better presentations. I didn't realize until I started fishing very small nymphs that the backward facing hackle helps tremendously to keep the line off the water. It acts like a sea anchor or drogue chute (works like a parachute under water). The forward facing hackle - especially when tied full rather than sparse - very definitely resists the tendency of the line to sag. Very similar flies are tied in the Sesia river valley in Italy, where the traditional fishing method also uses a long rod and horsehair line tied to the rod tip. The hackle is tied that way because it works better (when used with a tenkara rod and line). With a western rod and line, there is little advantage to the forward facing hackle.