I didn't mistake correlation for causation. More gay people don't have AIDS because they're gay, but it's still a thing. The correlation is still there which means a potential waste in time and resources accepting and testing blood that is more likely to be unusable and having to worry about false negatives etc. I don't agree gay men shouldn't be allowed to donate blood, I just understand why it's a thing. You don't have to agree with something to understand and empathize with it.
As for the trans/suicide thing, I'm aware that trans people aren't suicidal by nature and it's more circumstantial, but since the correlation is there, it means potentially allowing more suicidal people into the military. Suicidal thoughts/depression are hard to "test" for. It's a lot easier to say "Are you trans?, yes? K BYE". I don't agree with this at all. I just understand. Also since commenting I've been made aware it's a medical costs thing. I didn't realize the military would be made to cover trans procedures. In which case, I agree they shouldn't be allowed or the military shouldn't be forced to cover their health expenses. I think America's healthcare system is really stupid because if you ask an employer to cover someone's healthcare costs, you're giving them incentive to discriminate based on disability. Taxes should be paying for healthcare, not employers, because you can't just exile someone for being trans or pregnant or an amputee or whatever. It's a lot easier to just not hire them. America is fucked.