Guys and Girls

In most cases guys and girls cannot be friends (unless they are both married, engaged, seriously dating other people, roommates, childhood friends, neither one was interested in the other to begin with, gay/lesbian, and that's all I can think of right now).

An Example If You Will
The most glaring example of guys and girls not being able to be friends? When they have tried dating. For example, I go on a few dates with a guy. He likes me, but I do not like him which is why we are not an item. There is a strong possibility that I don't even like him as a person and / or would not want to be seen in public with him ever again.

To make my argument, I will say I become friends with the guy I don't want to date.
Top 5 potential issues?

1. I probably don't want to be seen with him. I meet a lot of guys at the bar when I am drunk...goggles much?
2. He was oh so charming when I was drunk, but in reality he is more sleep inducing than an accounting textbook
3. He doesn't have enough value add (personality, looks, generosity, sense of humor, intelligence, etc.) for me to want to date him, why the f*ck would I want to be friends with such a character?
4. If we were to ever go anywhere and a random guy started hitting on me I am sure he would be upset and maybe even c*ckblock
5. Because we are "just friends" the fool would probably want me to pay for stuff because he doesn't have enough class to realize 1) girls like me don't pay and 2) he should be lucky to be seen with me (especially in SF)

So I don't like him enough to date him, but I am willing to spend time / money hanging out with him? This is clearly not in my best interest.

No Hypocrisy Here
Yes yes many of my friends are guys, but have you noticed these are almost all childhood friends and I obviously like them as people...