I remember a brazilian gay group on Facebook did a poll if you would prefer have sex with a transgender female with a dick or a transgender male with a masculine body and a vagina and the results were like
70% male with vagina
30% female with a dick
Oh yeah it is a weird idea but I would have no problem with making sex with a transgender man.. I think it could even be a nice thing actually... I don't think I am bisexual for that... the idea of having sex with a transgender woman doesn't arouse me.. I am not that aroused by a dick and a dick only
The problem with cisgender straight people is that they treat that as something "wrong" and I guess they are equally aroused by the taboo
Brazil for an example (my country) transgender is one of the most searched type of porn in porn sites.. but we are also the country with the highest rate of transgender murders... here is higher than countries with no laws to protect transgender people