The only time I ever offer a draw is if I think it might be a draw. Offering a draw when your opponent is up 2 or more points is, in my opinion, either unsporting (trying to gain a draw in a losing position, or trying to throw one's opponent off his/her game), stupid (not understanding when one clearly has a losing position), rude (thinking one's opponent is stupid), or a joke (jokes don't belong in chess). Either way, it doesn't reflect well on the player making the "offer".
The only time I ever offer a draw is if I think it might be a draw. Offering a draw when your opponent is up 2 or more points is, in my opinion, either unsporting (trying to gain a draw in a losing position, or trying to throw one's opponent off his/her game), stupid (not understanding when one clearly has a losing position), rude (thinking one's opponent is stupid), or a joke (jokes don't belong in chess). Either way, it doesn't reflect well on the player making the "offer".