Because most stocks drop after a split. Who is going to pay for those extra shares? Look at apple when it split,it dropped like a rock also. its just the game the companies play.Look at the last split cxw had it dropped during that split. You don't make money on splits for a long time till it pays for itself.nothing in this world is free.
Actually split is nothing new. Nobody gains anything and nobody loses. The reason companies often drop a little after the split is pure psycology. If you have 2000 shares instead of 1000 before the split, its likely that you gona sell off half of your position. Thats what people do, stupid people actually, it only makes a great buying opportunity.