There will always be a good case to be made in individual cases for doing almost anything. It is what is healthy for society as a whole, the direction in which we want to go that is at stake.
And that is the whole point of the ACLU's case; that there is no rational basis for a blanket ban (no exceptions,
ever) on adoption by gays. They are simply asking that gay applicants for adoption receive case-by-case consideration, such as is given to
any other applicant for adoption, married or otherwise (including known substance abusers and perpetrators of domestic violence).
This Florida law is the kind of inflexibly discriminatory law that the courts have not shown much tolerance for. It's a stinker.