m-m sex is still disqualifying even if all parties are completely clean and safe. it's discriminatory.
I have never been able to donate blood because of my travels due to their locations and frequencies. I am not going to give up travel to donate blood. MSM is a much higher risk activity than travel, and yet I am also excluded due to my lifestyle risk. It's not fair, but it is reasonable.
12-15% of gay men in the US have HIV.
The rules exist for a very real reason.
Anal sex is inherently much more likely to transit HIV and HIV tests have a higher false negative rate for new infections.