There are 2 things I see going on here.
1) Multiple forms of bigotry tend to cluster together in people. Mark Robinson is a racist, a misogynist, a transphobe, and likely several other variants of bigot.
2) Even though many cis men publicly express virulent hatred against trans people, a good number of them fantasize about sex with us in the privacy of the glow of their computer screens.
Trans women are good enough to fuck but not good enough to treat as fully human.