Why the silent hate against weapon gems that fit multiple weapon types

So I've made a post while back, suggesting that Rolling Slam also be usable for Quarterstaff, to improve the leveling experience of Monks from levels 1-5 and for Falling Thunder to be usable while wearing a hammer because it has the potential of simplifying the early game aspect of warrior.

Is it too soon to start thinking of spreading skill gems over multiple weapon types when GGG hasn't released all the weapon skill lines yet?

I think things should remain logical: no slashing or piercing weapons doing "slams", etc. But in general I agree a lot of skills should be more open. I really want to use Rake with a two-handed sword when those are added.

My suggestion: add little tweaks to skills depending on weapon type used. Almost like weapon type is a support gem.

Both Quarterstaffs and Hammers can do slams.

The thread I'm mentioning involves allowing just some skills from Hammer and Quarterstaff to be shared among each other.