Kinsey, like every other social scientist since the Enlightenment, was simply obeying the central tenet of his  that the scientific study of society is possible; that the results of such study are a better basis for policy than, say, the Mosaic interdiction against homosexuality.
Kinsey believed in the superiority of the scientific method applied to all disciplines, society in particular.
Kinsey believed in that the Mosaic interdiction against homosexuals was a good thing.