Hand cannons have a high learning curve in pve and pvp alike. They are some of the most rewarding weapons to use but very unforgiving in the hands of the wrong user. Most people who pwn in the crucible with a hand cannon have worked at building their skill with one for a long time. Furthermore, pvp noobs stick to assault rifles(suros regime). I understand that the Thorn is powerful, but few would call it overpowered. The chances of you meeting a skillled player with thorn are slim. Out of all the players I've met in the crucible who wield Thorn, only one has really posed a challenge. Yes I died over and over, but he earned those kills.