Of course, one follow-on to "those who can't do, teach" is "those who can't teach, criticise". The term 'armchair quarterback' came from American football; it is all too easy for those without responsibilities to shout abuse from the sidelines, or for a critic to turn into a crank who cannot be turned from their chosen topic, nor acknowledge the potential validity of other viewpoints. Fans should beware letting their passion for the game turn to vitriol for those who choose to play differently.
The Onion has been making hay over this issue, most recently with an article about Penn State students and alumni.
Of course, one follow-on to "those who can't do, teach" is "those who can't teach, criticise". The term 'armchair quarterback' came from American football; it is all too easy for those without responsibilities to shout abuse from the sidelines, or for a critic to turn into a crank who cannot be turned from their chosen topic, nor acknowledge the potential validity of other viewpoints. Fans should beware letting their passion for the game turn to vitriol for those who choose to play differently.