From the posts I quoted in my first post we can deduce that all 3 of you thought that every single opposite gender friendship forged since the beginning of time had some sort of sexual tension or physical attraction, which isn't the case. It's certainly possible for platonic friendship to lead to a relationship (and most of the time we get our girlfriend/boyfriend from our friends, because we spend so much time with them anyway and know them well), but to simply write off that a platonic friendship with no physical attraction between the two persons involved is impossible seems a bit stupid to me.
I think it's fairly implicit within the confines of a consensual relationship that both parties find the other attractive (and I am not necessarily referring to just physical attraction here). Obviously if there's a friendship where one party does not want a relationship due to finding the other party unattractive, it will stay a friendship (the infamous "friend zone"...) or eventually dissolve.
Just because I find one of my straight male friends attractive doesn't mean I want to fuck all of them, and just because one of my straight lady friends finds me attractive doesn't mean I'm going to avoid all straight females.
If you find someone attractive, then that means by definition that you would be willing to fuck them. In this case, extenuating circumstances are present that prevent you from acting on that attraction...but you can't tell me that if a gorgeous straight friend of yours suddenly came out of the closet that you could maintain a purely platonic friendship devoid of sexual tension for much longer. It's just now how it works; human beings are hardwired to view all attractive individuals as possible mates, and a friendship will merely deepen that connection to the point where, if nothing else is in the way, romantic feelings will bloom.
But to say that platonic friendships should be avoided from the opposite gender is a bit silly and in my experience and from what I've observed, it's 100% possible.
My point is, if both parties are attracted to each other, then the relationship simply will not stay platonic for very long. I mean I know I'm painting with a pretty broad brush here, but I can confidently say that in 95% of cases where two members in a friendship find each other attractive without any other circumstances preventing the expression of that attraction, there will always be sexual tension in that friendship.
Edit: Chou, you're right in that female friends definitely make for different types of friends than male friends. It's a lot easier to be comfortable around them because there's no sense of friendly competition that's pervasive in male groups of friends, and they're a lot "softer" as far as companionship goes. There's nothing mushy about that.
The idea is not that female friends should be avoided...but that anyone who is willing to tapdance in that particular minefield is fully aware of the complications that they are risking.