When you make food you're compelled to write the ingredients. We tolerate these because they are obvious and trivial, but pedantically, food labelling laws also violate the first amendment.
Surely you recognize the difference between "you cannot go out of your way to do crime" and "your software must include this specific feature"??
> When you make food you're compelled to write the ingredients.
Well, the point about how this affects open source is that under a similar California law, every home kitchen would need to be equipped with an electronic transponder whose purpose is to announce to the world what ingredient bucket you used for tonight's casserole.
Anyway, the whole point of the metaphor, because I feel like I will have to explain it, is that we don't put these onerous "required labeling" rules in place for private individuals going about their own lives. So just like you don't have to tell anyone who asks what you put in your dinner last night, private individuals should not have to tell anyone who asks (websites, apps) what age demographic they fall into.
Note: this is one of many arguments I endorse against this type of law. This shouldn't be interpreted as "so that's all you're worried about?" just because we dissected it in detail here.