European versus American Museums

A minor comparison based solely on anecdote. I shot one picture at the Quai D'Orsay in Paris in August 2009 of Whistler's Mother forgetting to turn off the forbidden flash. Two guards walked past me from 20 feet away and merely smiled and said quietly, "no flash." I said thank you and turned it off. Similarly, I shot Picasso's Guernica at the Reina Sofia Museum in Madrid several weeks ago, deliberately breaking the no pictures inside the room rule, and certainly without the flash, and similarly the guard smiled, shook his finger and said in Spanish accented English (I guess I'll always look like an American on my travels), "please, not inside the room, you may shoot from the doorway."

All over the Prado I saw artists with easels doing copy work in oil in front of masterworks; not done very much here in the states, but this is an old established means of learning how great artists think, try to reproduce what they've done. It's harder than you think it might be at first try.

My questions are first why don't we see more artists doing this kind of copy work in American art museums? And what is the extreme bias that American art museums have against photographing "without flash"? I toured the Art Institute of Chicago's show of Benin Bronzes, where it was even forbidden to sketch, much less photograph. Why?