Backkick allows you to face your divers while maintaining a desired separation or closeness, without needing to push on them to prevent entanglement. Guiding involves maneuvering with one or a few divers, and responding to issues underwater that may involve fixing or adjusting their gear or responding to anxiety. If when you get close to them, you keep running into them because the only way you can move is forward, or you have to keep pushing away from them to prevent that, you have added to the problem. Frogkick is just a step before that, and a calmer way to move in the water with out kicking up the bottom.
+1. Seriously! Who wants a DM leading them around who is kicking up the bottom and ruining the viz?
When I DM for OW classes in the pool, I am back finning constantly to stay face to face with a student without us running into each other. Actually, ditto for DM'ing for tech classes. Even in an Adv Nitrox/Deco Procedures/Helitrox class, the first time a student attempts a valve shutdown drill, they pretty much all end up drifting forward as they do it. Some, only a little. Others, a lot. Likewise for shooting an SMB, if they haven't done it (or done it much) before.