I get all that, but sometimes you get mobs and summons of mixed race element, and you just want to hit neutral element.unless you have 1 mob or or many mobs of the same element. You rather hit hard or dont dmg at all. If it mobs with low hp it is not a problem but when they are200-300k hp thats a freaking headache lol
Even neutral got its counter, you never hit ghost element monsters with your neutral element 
and prepping things are part of any RPG based game, you need to know what you're dealing with and ready to counter it or at least be prepared for any worst case scenario 
btw RG is quite versatile, you got skills that are forced earth element and holy element and the rest of skills element can be altered through aforementioned consumables in my previous post. 
Even if you can't handle 200 - 300k HP mobs alone, you got choice to band with your party or guildsmate. Its as simple as that in any RPG based games 