Can guys and girls be JUST FRIENDS?

Why is it that nowadays guys and girls can't be JUST FRIENDS??? If a guy and a girl want to just hang out, almost everyone assumes that they are going to hook up and that they like each other. I have a friend Tim who is like my older brother I swear. We can tell each other everything and anything and talk about anything and not get uncomfortable about it because we are that close. We walk around campus linking arms and sometimes have our hands around each others waist as we attempt to walk without falling over from laughing and people think we are dating just because of that. There's this kid that I work with, Bill Mcleod, and I really like him, and I think he may like me but I'm not sure, and we were talking about this and he says he puts up with the same thing. We both agreed that by having a really good, close friend of the opposite sex allows us to try and figure out how the opposite sex thinks and interprets different situations. We are supposed to hang out this weekend and a lot of people that we work with know that I like him and that we are supposed to be hanging out and they keep teasing me about it because I think he likes me as just a friend but they are like "ohh he wouldn't have agreed to hang out with you if he didn't like you" and it's like uhh yea he could have.