Whenever I find myself taken aback or getting defensive by what is being said, I try to remember the adage: "separate the message from the messenger." Don't focus on WHO is saying it, or HOW they're saying it; instead, focus on WHAT is being said. Sadly, some people just do rub others the wrong way, and they may lack the proper use of tact and tone when asking questions or discussing their viewpoints.
Still, it is wise to treat everyone with politeness, even those who are rude to you--not because they are nice, but because you are. Besides, if your beer is good (and everyone here says it is)--that pretty much speaks for itself, doesn't it?