Most places already have laws making homosexual "sexual activity" illegal. Or did up until the terrible Texas case at couple of years ago.
And there are still laws making the bearing of children out of wedlock illegal. And yes, most definitly -- homosexuality should be a bar to adoption. Perhaps it still is in some states. Truth is we'd have less adoptions to start out with if high-profile high-status examples like Mary Cheney would be good exmaples, but by bad example they rob many of a decent life who would follow their example but in less fortutious and wealthy cicumstance.