A lot of gay people are kicked out of their homes as children, because they are gay.
A lot of straight people get help from their parents that allows them to purchase their first home.
These are likely connected to that 5% difference..
Also, what's the cost to medically transition in the states? I bet that also prevents you from being able to get a down-payment together, even if you don't face workplace issues stemming from you being true to yourself.