Bad / Unfriendly
unforgiving - Not making an allowance for error or weakness in others; not willing to forgive others for things they might have done wrong.

Because they knew that Alaska in the winter is an unforgiving environment, they had to plan their expedition very carefully.
intolerant - Refusing to allow others to do or believe things that you don't agree with.

When people try to dialog with others, and both are intolerant of each others' points of view, it often just degenerates into a shouting match, with neither side listening.