Based on the statistics above, just consider this.
You're in need of a blood transfusion.
There are two bags of blood to choose from.
Bag 1 is labeled straight blood.
Bag 2 is labeled gay blood.
Based on the statistics alone, bag 1 would be the safest choice.
Now why even introduce option two into our blood supply?
Yes there are screening processes, but they can fail, and with more gay blood to screen, the chances of failure also increase.
Is it really worth our health, just so we don't feel all mean about "discriminating"?