Average joes on the street don't care. No.
However I think the fanboy flames are often faned by the industry on purpose. Be it the websites that can generate traffic off of the back of a boisterus headline, or the platform game box that proudly displays in bold text the words EXCLUSIVLY FOR. Fanboyism can also generate word of mouth. I am sure most of us are known as "The Gamer" in our families/social circles, I know I am, and as such my recomondations can sell a lot of hardware/software. If, when asked, I said, "Bah, it doesn't matter what you buy, they are all the same anyways", somewhere a PR suit would die a little inside.
So I think fanboyism is actualy something the industry sees as a tool. Something that can build passion and move product.
As for people being assholes on the web over games...that has more to do with people being assholes then the actual games. There is zero reason to attack someone because they post "I don't like Sonys first party games, never have". And, yes there are dozens of other example statements too.
But, what some fool on the interwebs enjoys playing, shouldn't effect your own enjoyment of something else. Or vica versa.
On a personal note, I have grown very tired of it, and ultimatly of game websites over the past couple of years. In large part due to the robust display of fanboy zest. Weather it fits someones perception or not, I do actualy play alot more then Nintendo. And enjoying their hardware/software doesn't a raging lunitic/fanboy make me. And most importantly I should never have my personal char attacked because of the video games I do or don't like.
But again some people, esp behind the anonomus cover of thier screens, tend to act like assholes.
I believe that banter on such a level is why a lot of long time posters have fallen back to just lurking or stoped logging on all together.
I don't think much can be done about it. If you are going to allow anyone, unrestricted acsess to post, your going to get all kinds. The more extreme posters will drive away more casual, less dedicated, and even the more moderate posters. Squeeky wheel, oil and all of that.