(oh, you make it harder for me to believe you are not a troll.

actually refering to COD... oh, the perfect stereotype)
anyways, serious now...
it is fun your YOU. that's totally valid. but how can another player counter an invisible sniper? it's not possible. you get a headshot from someone you didn't even see and that's it. this is what negative gameplay means. it's fun for you but not for everyone else.
there needs to be something that can counter the cloak more effectively. there is decoy that un-cloakes invisible players that are near you i think but that's probably not enough. especially not for a cloaked sniper that usually is not in your vicinity.
or you get a negative effect from cloaking, for example, it slows down your movement while you are cloaked. this would at least help a bit against the invisible shotgunners. but this would affect the ability in pve also. so, it would actually affect even more players that use this ability in pve.
the really easy fix however would be to simply disable the active abilities in pvp. band-aid fix, i know but at least it would even out the playing field and trion can work out something else. heck, generally speaking, i don't know why one of the active ability makes the player invisible. did they want to have some kind of rogue class like in world of warcraft? coze, every l33t kid wants (why did i type once instead of wants?) to play the rogue? really bad they put this into the pvp mode. invisible players in pvp. that's just fundamentally wrong.
btw. i havn't played pvp yet and i'm not planning to until trion fixed this. right now i'm just speaking on a philosophical level.