Whether or not keeping guns in a safe will stop a determined criminal or not is almost not important.
Remember the antis aren't logical thinking people, its there feelings that count not logic, but even its not just the anti that you need to keep quite.
Its the majority of the population that the antis are getting onside with that will be the ones that force politicians to make legislation on gun control.
Politicians aren't going to have 70% of the population screaming for gun control but the rest convince them otherwise, politicians are going to do what will get them votes, not whats right.
(70% being a guessed figure).
People should do everything they possibly can to convince antis, and the rest that gun owners are doing everything they possibly can to shut them up.
Yes a determined criminal would most likely be able to break into a safe, but if someones in to just grab a few things and go, isn't going to take the time to find your safe and then try break into it.
And to protect children from guns, as children are well known for messing with things, and if they find a loaded gun, or their friend finds one they are going to most likely play with it.