I don't see female colleagues at my current job as friends and I feel the same about the girlfriends of my friends. Those are just platonic relationships to me that I am not interested in deepening in any way.
Or are you talking about sexual attraction? Do you view women as only sexual? I am simply trying to figure out what men provide that women can or do not.
Personally (as a man) I can't make heads or tails out of how to interact with other men outside of work; I am precisely the opposite of you.
But at the same time I think men are generally more fun to be around. Woman are in some way 'less funny' on average.
But now I have a wife and a baby, so I will not bother with other female relationships anyway. I like to keep things simple in life :)
if that is the case, it doesn't sound like you are actually pursuing friendships
Personally, I have plenty female friends with whom I know there is no attraction.