Can we all agree to this? It's not like it proves how "badass" he is; Mark and Execute, sure, fine, whatever, but what the heck does Sam having a never-ending stash of pistol magazines prove? Notable games like Call of Duty and Battlefield and Resident Evil don't do anything like this, so pressure couldn't have been a factor in Ubisoft coming to the conclusion that they came to. Is it an abridged way of showing how he's so adapt with his signature Five-seveN that he can scavenge ammo for it on a whim, similar to how the pistol also has the highest available marks to use? Well, OK, but why does this also apply for other pistols?
Some who frequent these forums posit that, because this is a stealth game, the player is not supposed to be shooting much, so this is a non-issue. Alright, but why doesn't this logic apply for the rest of the weaponry available? If it's because of balance, then there should be no infinite ammo of any kind. And why not limit pistol ammunition if players aren't expected to go on a shooting frenzy? They won't be bothered that there's a limit to their shooting if they are indeed playing stealthily, and it will lend the next installment a little more air of realism and further refine gameplay balance.
So yeah, I see zero reason for Ubisoft to continue this practice.