The Hyouton specialty focuses on the manipulation of preexisting snow/ice/frost/Ditto/that-icecream-Pokemon (influenced by the first movie), whereas the KG focuses on creating ice from thin air (or something like that).
There is a point in still having it, though it isn't very dominant.
Having a kenjutsu specialty on the other hand would make next to no sense whatsoever were somebody with no in-game weapon (say, at rank 0) able to use it. Similarly it wouldn't make sense to make a specialty rendered insignificant to every other one just because a character lacks a purchasable item.
I understand the issue you have with Kenjutsu, especially with those people who are physically unable to purchase a weapon; but I do think you are being a bit confrontational about an idea I was proposing as an alternative, especially since I did say pretty clearly that I was sure there are other alternatives.
Hyouton, as it stands, sticks out as the specialty that makes the least amount of sense because of the KG. I understand the 'pre-existing snow' argument, but to be frank, the information we have about Hyouton Specialty comes from a Naruto movie which has no official baring upon the canon plot. Hell, the movie from which Hyouton Specialty derives also features guns, trains, cars, and movie theaters--maybe we should have some of these in-game? I'm pretty sure its ratings aren't very good, either, and though I can't remember where, I'm pretty sure I read somewhere that even Kishimoto was disappointed in this movie.
In the rules people have tried to draw up concerning SL RP, even, Hyouton is treated as a KG, not as a specialty. If there is a 'reason' to have a Hyouton specialty, you are right, it certainly is not dominant at all.