It's not that hard to fake what is and is not a bomb in space. Consider their is no air resistance so use an inflatable balloon which may or may not have a bomb inside. For 10,000 kg you could probably send up 100,000+ fake bombs which would all have slightly different vectors making hitting them all very hard. Further, if you use something mechanical vs inflation it's not obvious if something was shot down or not.

Worse, the attacker may feel they can use something like that while shooting down any responses.