Though rationality certainly disappears among some people when their tribe is under attack, I fear this is being used as an excuse for shirking any form of loyalty whatsoever. Orwell's definition of patriotism is too brief, and seems to me a toothless one; it can't accept anything more than the most transient loyalty. A man without such loyalties is quite fit for a journalistic trade, but I fear such a man is not rooted enough to be of great use. He is like a homeless fellow who, after dispensing some wisdom here and there, will not accept an invitation to shelter for fear he'll be compromised, and so his few insights are left in abject vagrancy.
But those who cannot ever admit the shortcomings of their own side are doomed to have their opinion become irrelevant to any thinking person.
I had an extended discussion a couple of weeks ago on FR with a Catholic who was essentially unable to admit that anything evil had ever been done in the name of Catholicism by ardent Catholics. I finally asked him/her why the Pope seemed to have no such difficulty and received no reply.
There is only one Man, I believe, who has been without fault. The rest of us shouldn't get overly defensive when accused of wrongdoing.
We should, however, focus on the net record of an organization or individual. Another friend of mine is a Socialist (really!) and he assigns blame to America for essentially every negative trend in recent world history. America ain't perfect, but it has probably a better record of doing good than any other powerful government has ever had. (It isn't difficult for Switzerland to avoid conflict with others.)