If you don't see the value of carrying 17 rounds - why bother carrying a gun at all?
You don't get to choose how many killers are going to outnumber you and your family. You can bet they will not be afraid to carry more then 10 rounds.
Well, I
thought you were going to say that if you don't see the value of carrying 17 rounds, why carry a gun as
big as the G17. I could sort of see that. And the response might be "Because I shoot it really well." That seems reasonable, too. But you seem to be saying something more. Now a 10+1 semi-auto isn't worth carrying at all because of the multiple-assailant scenario involving an arbitrary number of attackers?
Here's my problem with that argument. A regular Joe out and about doesn't win a gun fight against multiple assailants by carrying more rounds. That fight is not likely to end when the multiple assailants run out of ammo, no matter how much ammo Joe is carrying. If regular Joe wins that fight, it'll be because he put more rounds on target first, and probably because some of the multiple assailants decided they didn't like their odds after seeing a couple of their buddies go down. Otherwise, regular Joe is going to die with rounds left in his magazine even if he only has a 10-rounder.
There might be a scenario where we fine tune the number of attackers and tweak it just right, but what are you really doing here if not trying to justify something that you decided before-hand without
needing any justification? If you want to carry a G17 with a standard mag, be my guest. I'm not saying anything about that. I'm just saying that the multiple attacker scenario outside the home (where you don't get the luxury of fighting from cover or concealment, either one) is a fairly weak argument against 10+1 being enough because the more attackers there are, the sooner you're going to be taking hits. Plus, if you
do get to fight from cover or concealment, a spare 10-round mag should make up the difference.