That's 29% that joined for financial stability, not that they had no other options. There are many that join because they are destitute, and I won't blame them just like I won't blame the few in auschwitz who stole from others while starving. That is absolutely not the majority though and most are there because it was convenient for them or high paying.

The cook is not equally responsible, just like a getaway driver in a bank robbery is not equally responsible, but they are still massively aiding the perpetrators. If every cook quit the military, would that not have a massive negative impact on military operations? Lower morale, harder to get certain types of foods eaten, more waste, food is one of THE most important things for a military.

You can argue the extent of the impact, but it's one of the biggest deciders of morale, and no chef means massive morale hit, which means less willingness to follow (in trumps case, illegal) orders, less willingness to remain in the army, and worse overall performance. By providing that service you are significantly increasing the effectiveness of the military. That doesn't make you the same as the person shooting the gun, but you still carry a lot of the responsibility for it happening.