In true etiquette the American flag should never be considered, or fashioned into an article of clothing.
Funny how some patriots out there will go to a 4th of July Parade and get mad when the beloved Stars and Stripes just grazes the pavement, but will then go home and throw their flowing American flag t-shirt into the dirty clothes hamper.
Its an example of misguided patriotism, and wearing a shirt has never...and will never...be the way to show you're a patriot.
Wearing a FLAG as an article of clothing is bad etiquette. Wearing an image of a flag on a T-shirt is NOT bad etiquette. I think one should know the difference. The etiquette part came about on how to properly DISPLAY a FLAG. It did not reference or mean to include articles of clothing that happen to have the image of a flag. a T-shirt is NOT a flag, and does not carry the same applied etiquette.
If that was the case, we all fold up a flag on the dollar and shove it in our pockets and sit our butts on "flags" every day.
It's has nothing to do with etiquette or displaying the flags. But as usual, this type thing gets bogged down on minor detail and we miss the broader points of freedom and liberty. Something many are willing to throw out in the garbage with the flag.
I think to judge a person's patriotism based on wearing a flag, is about "misguided" as the point you made using the term "misguided". There is no way you can judge, reference, or somehow scale, a persons patriotism based on YOUR opinion of what another does, does not do, or how one uses a flag.