No one is asking you to care about them.
The question is whether or not you honestly think sending these people to prison for 10 years makes any sense. It's the same thing when some poor black kid gets caught with some weed and goes to jail. I'm not going to lose any sleep over it, and it's easy to point at their actions and say they were "idiots" for doing drugs and carrying it around them, and that they were "flouting the rules" by having a controlled substance. But I also know an injustice when I see one.
And there is precisely zero indication that these people are "flouting the rules." This would actually more likely apply more to the kid with some pot, because they know it's against the law and they likely know they have it on them. Why would you bring a handful of ammo into a country on vacation with no gun or anything? Hell, even if you had a gun, a few rounds isn't going to do much.
You're trying to paint it in the worst possible light. Slow down, take a breath, and think about this rationally and objectively for a second. Does this really solve a problem? Is this a good thing for our society? At least one of these people is a parent, do you really think it's great they lose their parent for 10+ years because of two bullets accidentally left in a bag? I just can't fathom how anyone sees any justice in this. There's no requirement that you think so vengefully.