I'm not sure I agree in this case. The Oxford English Dictionary gives ones of the definitions of guy as 'people of either sex' [0]. There's value in defending this meaning, and not running away from it because it could be misinterpreted. This is similar to how geeks like to defend the positive definition of 'hacker', rather than avoiding it.

To be clear: I'm not trying to minimize the feelings of women or other marginalized communities. Rather, I'm just saying that one way to respond is to aggressively 'colonize' words so that a positive meaning becomes the dominant meaning.

[0] http://www.oxforddictionaries.com/definition/english/guy