Not true. You may not be attracted to women, but if someone offered you $2000 to make out with a woman, and you said, "Well...I really need the money. Fine. I'll make out with this woman." And you make out with her. And you aren't turned on at all. She is beautiful. Gorgeous even! But you just aren't attracted to her. But you make out with her for $2000. Then they want you to have sex with her for $5000. And you say, "I won't even be able to get it up. She doesn't turn me on. I like MEN!" So they say, "No problem. We'll give you an injection and your dick will get hard and you can fuck her." You really need the money too. Those bills aren't going away. Fine you say. You do it. So you fuck her for $5000. Does any of this mean you aren't gay? No. You still are attracted to only men. So later in life you retire, and marry the man of your dreams. And people say, "He is bi. He use to fuck women on camera." No. You're gay. You did that for the money. And you didn't sexually enjoy it. You just did it for the money. It is possible to be Gay 4 Pay and be straight.
TLDR: If a gay man can fuck a woman for money and not like it, a straight man can fuck a guy for money and not like it.