Well first off, you're limiting your Destiny experience therefore making you a lot more bored with the game. Secondly you're missing out on unique exotic armor for the other classes. Thirdly you will miss out on two of the three new subclasses with Taken King, and whatever class exclusive guns the other two classes will have. And what if one of those class specific weapons are very powerful and unbalanced at first? You'll be at a disadvantage. The final reason I believe you are extremely dull in the head is because you most likely only play on one of your Warlocks most of the time, therefore making the other two Warlocks completely useless. Instead you could have made only one Warlock and then have a Hunter and Titan to experience more in the game. And we don't even know if the new subclass storylines are separate or not from the main campaign! And if that's the case you just flushed about $20 down the drain because of that amount of content you lost. I'm not trying to force you to do anything about it though, and I can't really do anything about it. But I can explain to you with full-blown 100% true knowledge that you are putting yourself at a disadvantage, missing out on the full Destiny experience, and overall giving yourself a large setback as a Destiny player.