Because Gossip Girl is doing it 
Now seriously, major lovefest spoilers below :
W Well, Kerry, everyone knows that happy couples equal deadly-boring TV. They had to break them up. The good news is that the spring episodes are promising a major lovefest when three (yes, three!) couples reconcile within the space of a few weeks. On the other hand, Teddy Montgomery and Kelly Taylor will be left out in the cold. by TV Guide
