I wanted to add to this. You often have to be sexually positive if you're transtioning.
You've been in the wrong body for years, been denied engaging with other people in the way that feels right for you, and now you have to make up for potentially decades of sexual and intimate inactivity.
Add to that the world certainly isn't going to praise or accept your sexuality, or know anything about it at all, and that you have to defiantly assert your sexual nature in order to be recognized as having one at all, and you can start to get the perception that people who are transitioning are overly sex-focussed or sex-positive.
In reality society really really really really really wants trans people to dissappear, or failing that, they definitely don't want them to have a sex life or to be any kind of open in public. Once you're on the margins like this, already completely rejected and incapable of being socially acceptable, there's no reason to not just do exactly what you want all the time. Snuggle up to someone you like in public? Yeah, why not, society retches when it sees my adams apple anyway, so its not like some weird stares are gonna discourage me.
Talk openly about my cabinet of sex toys or the threesome I wanna have tonight? Yeah, definitely, I've already got enough people calling me a freak tonight, it's not like them reasserting it is going to make me feel less safe.
I think everyone really has similar desires to sex-positive trans people, they're just holding on to society's acceptance by their fingernails instead of letting go entirely.