"Improper[]" regulation of "public morality"?

Thanks to Michael for posting the news about the recent Arkansas decision about foster parenting.  (I thought it was particularly interesting that the court declined to reach the equal-protection and privacy claims, and instead concluded that the regulation against foster parenting by gays and lesbians violated separation-of-powers principles.)  Justice Corbin's observation that, based on the lower court's findings-of-fact, "[t]here is no correlation between the health, welfare and safety of foster children and the blanket exclusion of any individual who is a homosexual or who resides in a household with a homosexual", seems unremarkable.  But, can it really be true that it is, as a general matter, and absent a claim that the regulation burdens particular legal rights, "improper[]" for the state to "regulate public morality"?  Don't governments "regulate public morality" all the time?