I agree. That reasoning would happen prior to the bad stuff happening for some, but it would have a deleterious effect on the ranks over time.
There are just a lot of other issues I can think of. For instance, the #1 rule of insurgencies—be more popular than the invading force. AQI was TERRIBLE at it, and that’s why they lost. Well, it would be easy to paint an insurgency in the US as killers of brave Soldiers and Marines while it’s very clear those same forces are using non-lethal weapons to detain (we have tons of non-lethal stuff from GWOT). That’s a major PR bust right there. Also, the military can render aid that insurgents just can’t, so that adds to the cumulative effect.
It’s a tough nut to crack, no matter how it goes.