Some people do but those are usually smaller voices from a smaller audience.
It is far more convenient for people to boycott other peoples' military/police institutions than their own, thanks to decades of pro-military, pro-police propaganda.
People will cry bloody murder if China does military exercises somewhere but when America sends her freedom loving troops to shoot brown people it's often "hoo-rah, America fuck yeah". Rare is the person who's a universal anti-imperialist.
