“If you have trouble grasping why, just imagine if the military had a “don’t ask, don’t tell” policy for adherents of the Muslim religion (any and all brands).”
The FDA bans any and every homosexual from donating blood in the USA. Do you understand the reason for that and the tremendous threat it would cause to the military’s combat blood supply?
The military tests its members and prospective members for AIDS and hepatitis, and won’t let anybody serve or continue serving if they test positive. Face it, lots of heterosexual male service members frequent prostitutes and can easily get infected with HIV that way if they aren’t very careful. If there was a chronic shortage of blood for civilian use in the US, the FDA would change that rule and require additional testing of the donated blood instead — as it stands now, the additional blood isn’t needed and increasing the testing procedures would just drive up the cost of blood.