Huh? What sort of complaint is that. If they made mouse 1 Plasmids and mouse 2 fire I would change it BACK. Mouse 1 is fire your gun in every game since the dawn of gaming (not literally), changing it for the sake of orientation would be stupid, besides, can't you swap hands?
I just can't seem to get a button configuration i'm happy with. Mouse 1 = fire, Mouse 2 = zoom/sights is common, so i've had to put plasmid as Mouse 4 and melee as Shift. I should probably change those 2 round and have melee as Mouse 4 like i used in CoD4 and Shift as plasmid... no doubt i'll end up trying to sprint and using a plasmid ><