Because if I drop it I don't want it to go off. Because it was the way the gun was designed AFTER the military made JMB put a grip safety on it. Because it is the safest way to carry a 1911. Because a flip of the safety and good to go. It is the safest way as pulling the hammer back in stressful situation could go wrong and cause a bullet to go down range when it needed to stay in the gun. Want more?
I think this thread has run its course. The OP asked a question, got his responses, and yielded to logic some time ago. Coming here and making additional posts that cover what has already been said accomplishes nothing, let this thread die.
"They who can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." -Benjamin Franklin
"The whole of the Bill (of Rights) is a declaration of the right of the people at large or considered as individuals.... It establishes some rights of the individual as unalienable and which consequently, no majority has a right to deprive them of." (Albert Gallatin of the New York Historical Society, October 7, 1789)
"A free people ought not only to be armed and disciplined, but they should have sufficient arms and ammunition to maintain a status of independence from any who might attempt to abuse them, which would include their own government." - George Washington