Even if you buff the other stances, there will always be 1 best stance to use, even if its 5% better, people will use the best stance. Buffing them merely gives you the illusion of choice.

Also not all skills need to be viable. Every class has at least 1 skill that hardly sees any use. Paladin the best tank or whatever? Tempered Will is hardly ever used in 95% of the content, 5% being o4s. Shield Bash?? Most of these skills are there just to give some sort of flavour to the class. If the skill has its niche use, then its already pretty good for a filler skill. People are just bitching cause it happens to be in your 60-70 rather than being a niche skill in 1-50..

If any changes are to be made, then the stances should directly be in the rotation, isn't of having a "best" stance, like start if wind makes your buffs/debuffs longer, so you always go to wind in opener, and switch to fire later on, then back to wind to refresh debuffs/buffs. Earth is fine as some sort of migation with its niche use.