It's not hard to flip that safety off when you draw. It doesn't add ANY time to the draw.
Go to an action shooting match and watch the guys shooting 1911s. These are guys who practice regularly with their guns, and yet not a match goes by when someone doesn't fumble with, miss or forget to flip off their thumb safety. And these are guys who are prepared and know they're about to draw and shoot. Can't imagine what the results are when the shooters aren't prepared.
1911 fanboys love their guns and tend to be super defensive about them. And if that motivates them to put the time and energy in to training with the gun, and they shoot the gun well, than fine. You can't argue with results. But for a new shooter, it's not the best choice - technology has advanced in the last 103+ years, and there are better choices out there. And if a new shooter is making their choice based on the faulty assumption that a manual safety somehow makes a gun more safe, than they need to better educate them self before they make an important decision.