Sounds like you are conservative in your relationships. You might lean left in your politics but still be conservative in your personal values. I think that is your case.

But many people have friends of different gender than them. You can even be friends in situations where there is attraction but none of them want more than friendship. It also happens.

When you say it is a myth, you are projecting your own feelings into others. If you would fuck any woman who is friendly with you provided that you have a chance, that is on you. But many people are happy being just friends and never making it sexual.