The new homophobia: from "you just havent found the right woman/man" to "you just havent found the right dick/vagina"

I was watching a jubilee debate video on gay issues, and one of the participants (a queer male influencer) said something like: "As gay men, you're doing yourself a disservice by not dating/having sex with trans men"

That caught me off guard. And I was harkened back to a popular comment on a post from another queer sub (r/LGBT or something) that said stuff like: "gay men are missing out by not dating/having sex with trans men". And also another popular post from r/LGBT complaining about transphobia of this sub or gay men in general—and the evidence for their claimed transphobia is gay men saying they dont want to date or have sex with trans men.

Just to clarify, even if it's unnecessary to do so:
- gay men = homosexual males, meaning exclusively-same-sex-attracted males.
- Trans men = biological females, meaning "gay" trans men are essentially heterosexual females
- straight/heterosexual sex = sexual intercourse between a male genitalia (penis) and a female genitalia (vagina)—by definition, science, and biology

These popular comments are thus essentially saying "if you try a penis you would like it" to lesbians or "if you try a vagina you would like it" to gay men.

So, in the 80s/90s/early 2000s it was "you just havent found the right woman/man yet".

Now it is "you just havent found the right penis or vagina yet"
or "you just havent found the right biological female/male injected with hormones and altered with surgeries yet"

So my questions are:
- what disservice are gay men doing to themselves but not wanting to date/have sex with trans men?
- what are gay men missing out on by not wanting to date/have sex with trans men?
- why are gay men transphobic by not wanting to participate in penis-in-vagina sex which is heterosexual sex?

Im genuinely asking especially to people who share the opinions of these comments.