Are the Mumbai attacks proof enough that banning guns is no good?

I have yet another point that became once again even more evident with the recent attacks on hotels in Mumbai. Now, the 5 star hotels in Mumbai are just like any 5 star hotel in New York, which are the same as any building in America in this regard: Approaching any building today in the world, one is greeted with a sign that reads: "This building bans guns in these premises." The purpose of these signs is to hopefully keep us safer from vicious attacks with armed weapons. However it does nothing but put us in mortal danger by un-arming law obiding citizens who could defend from people with grave intentions. But wait... How could ALLOWING people to carry guns make us SAFER? This is where the Mumbai attacks come in. This is what happened in a nut shell: A hotel full of people who are law obyding citizens, occupied the hotel. As they do obey the law they wouldnt think of carrying guns, as they would not like to be arrested. Then, terrorists who could give a damn less about the "ban gun" signs storm the hotel with a mission to kill. Thanks to these wonderful signs, we disarmed anyone who could help save the day, prevent murder, and stop the terrorists from doing so. The bad guys still won, and are winning still, as they are still in control of half of Mumbai. Good people simply waited in the dark, under their beds counting the seconds until enivetably being "picked off."

Now here is another way this situation could have played out. If we were to remove the gun bans, yes the terrorist attack may still occur. However with the removal of the ban, perhaps one out of 25, or even one out of 50 good guys would have an armed weapon. In a situation such as that in Mumbai, there is at least a more even playing field. When armed terrorists knock on a persons hotel room, instead of surrendering, one may fight back against them.