I like it when characters aren't friendly all the time. It's more realistic that you will eventually come across a grumpy fellow who doesn't like you instead of everyone wanting to be your five-second friend. At least have some negative thoughts! I know I personally don't always say what I'm thinking.
I understand that no one wants to start any wars, but that doesn't mean people should confine themselves to being bland and 'nice' all the time. That is what most middle-aged women are like at business parties and we do NOT want to venture there yet.