Why

I dont know why, but it seems like as guys get older the more and more they think that they cant have a girl as a friend...well to me that how I see it. Im always use to hanging with the guys and stuff like that, but why does that change? Think the only reason why is that they dont want people to think that they are dating, so if it starts to be like that then it the ohh got to back off before she thinks it something. It just sucks, cause if I dont even like him he thinks it. It just stupid and if I want to be a friend to a guy and not be his girlfriend think I should be able to do that.