Usually this boils down to a false equivalence that is instilled into people through culture or propaganda. "I support trans people but think pedophilia is bad" this comes from people who realize trans people themselves are not a "danger" to people but still believe that they are pedophiles more than cis people. Or how people will support trans people but not gender affirming care. These ideas are hard to get rid of because they are something that are part of the core worldview of these people usually but them accepting trans people in any form shows that they at least want to change which is the most important thing and is easy to build on. Anyway, im cis just thought i could add my experiences as an ally and someone who grew up in a very anti-queer country.