There's a lot of controller-hate floating around (I've heard some hardcore jp FCs are booting/refusing people if they use a controller), but there's also the fact that the world's first solo-heal T9 kill was by a scholar using a controller. I personally think a keyboard and mouse is much easier and allows a lot more flexibility in customising your UI (and a whole lot more keybinds too), but we have a bunch of people in the FC who swear by controllers too. So really, just use what you like, the game is really accessible to both.

Btw, which server did you start a character on, Ergroilnin?