Now I would like to be more precise: I assert that, at the very least, male-female-friendship is a deviation from the rule. I.e., it is not expected to work, but it can in some instances.
Why?
Because male and female are by default and by nature sexually attracted to each other, and if not then that is simply unexpected.
In fact, there are studies where they made strangers simply look each other in the eyes for a little while. What happened was that some of them fell in love just by doing so.
Put another way: Friendship means affection. There is no reason why such affection between a heterosexual male and female wouldn't eventually cross the sexual level of affection, at least for one of the two. It is simply to be expected more often than not. Thus it is expected that at least one of the two will - at least occasionally - have sexual fantasies about the other.