Well, you are right. Thorn was actually a challenge to complete, (solo, without cheese) but getting the bounty itself isn't difficult at all. It is somewhat random, so again, you have that. But you do not even have to do endgame content to get it. Vex Mythoclast can be obtained only through VoG hardmode, so it being powerful makes sense, but even that gun was nerfed. In fact, the saving grace of Thorn is the fact that nearly everyone can use it, thus leveling the playing field. But wait, now everyone uses it. It's just not fun/good for Destiny. It really needs to be looked at and balanced in a way that still makes it good enough to use in PvP but not overpowered to the point where 9/10 players use it in certain game modes.