Maintaining secrets is a good reason for shooting down a surveillance satellite, even if the only secret is that the intelligence it provides is no better than commercially-sourced data. (Let's hope that's not true, but given the fierce drive for privatization under Regan and both Bushes, it may be closer to the truth than many expect.)

But surely the other point to the shot was the shot itself. It seems to me that the odds that a tank of hydrazine could survive re-entry is a remote risk indeed. But even large chunks of satellites can give very useful insights to people who should have to work harder for them.