you could say the same thing about many government employees. Defense contractors eat up a huge amount of tax money.
Without the defense contractors, you won't have any of the technology that gives our military the edge over our enemies. There are legions of government employees who could be dropped immediately with no impact on our ability to defend the country. Defense is about 18% of the total budget and is one of those items constitutionally authorized. The entitlement programs are the lion's share of the budget and unconstitutional.