As Christians we are to look at this from God's point of view, not the secular. So how does blood from gays fit into God's plan? I can think of many things about God that applies. God relates blood to life in many ways.
This blood from gays represents giving life to others, it doesn't represent being gay. Gays are outside of God's plan for them. That doesn't mean that God would not welcome them with joy at their return, or that God would say they may not help bring life and joy to others. Or that it is wrong for us to accept that part of them.
So, as Christians, we should choose to die before letting someone that is gay donate blood to save us? ......ooook