Unexplainable pet peeve: I hate
it when sports coats in general are called blazers. Double breasted blazers have a nautical origin and single breasted come from the club jacket (as pictured above). Paired with gray trousers they can be just a notch below the suit in formality. Quite frankly, I think everyone needs a navy blazer.
I sympathise with your sentiment. Sartorial misnomers are disproportionately annoying. You will be pleased to know that in the UK we never call sports
jackets 'blazers' - nor do we call jackets 'coats', or trousers 'pants', or pants 'shorts', or waistcoats 'vests', or vests 'undershirts', or Fox News 'balanced', etc. etc. The other day I was reading a report by a US Army officer, on exchange duty with the British Army, on how he found his posting - a whole section was devoted to the confusion caused by the above dissimilarities in descriptions. Two nations, separated by a common language.....