Red and white stripes, a blue field, and white stars does not mean it was made "from" the Colors. This is clearly not, in fact, made from the Colors, any more than bunting is.
Some people just like patriotic attire.
I would opine that the Patriotic Poncho is only a "Shoot Me First" garment in Portland, or perhaps in Eugene. Everyone I know in Salem would be more likely to shoot the antifa goon that looked like they were going to go all "Their free speech is violence, my violence is free speech" on them.