It is always strange to hear job creation used as a blanket defense for policies that deserve a much harder moral look. If the only way we can justify an industry is by pointing to the jobs it creates, then we are not really talking about prosperity anymore. We are talking about avoiding the deeper question of what kind of work we want to encourage.
Selling guns may move money through the economy, but that does not automatically make it good policy. A healthy economy should be able to create work by building, repairing, educating, inventing, and solving problems. When jobs are tied to spreading weapons into already unstable places, the cost is not just measured in dollars.