"Everybody does it, so it's OK." That's the rationalization of the cheater.
I for one do not and never will use gem exploits or any kind of exploits. Every BG I enter I now examine all other players. If I see a 24 with a gemmed item I screenshot it and report the player for cheater.
Who cares if 'sploiters corrupt and ruin the game?
I care. If I see you doing it, I'll report you. If I see you on the other team and you appear to have far too much stam or hit way to hard or end up with three times as much DPS as the next guy, then I will change toons and queue up for BGs until I end up on the same team with you. Then I will examine your gear, take screenshots, report you, call you out as a cheater on the forums, and post the photo to my Photobucket account.
I've removed friends from my real ID list for using gemmed items in the 20 - 24 bracket.
Using the gem exploit is an admission that you are too lame to compete honestly.