This has been previously discuss over here
http://forum.square-enix.com/ffxiv/t...lick-attacking
This issue has been there since when it begun.
Developer never bothered looking at it seriously. A game with both left and right click registering as select is just plain silly and stupid. No players complain and apparently everyone was happy with it. So it requires your extra careful attention not to accidentally select things that you don't want to.
It's like paying for a car that do not have handbrake. You ask your car manufacturers, they tell you off that handbrakes are unnecessary since you have brake pedals already.
We're talking about a highly reputable game company, not some china/korea game makers where silly bugs are understable .