Who said anything about laws? Apple's rules are no different from HN's rules. And for that matter, your house rules. They're arbitrary decisions to the liking of the respective party. They just have to not be against the law themselves. If they are problematic the solution isn't to generically "ban rules" (saying it out loud already hints at the "value" of this proposition) but to change the law to prohibit certain rules.
This is a super naive analogy - HN doesn't serve close to 50% of the US market, nor is it a platform through which billions of dollars transact. If it did very different rules apply, rightfully so, scale matters, market position matters - from Apple profit margins it's obvious they are abusing monopolistic position.
It's only naive because you chose the naive interpretation, based on sentiment and you not understanding the massive difference between laws and a company's rules. Until you understand what they are, and who decides if rules are against the law or not, mentioning "profit", "scale", "market position", and "different rules apply" doesn't get you closer to the point.
I'll take it down a couple of notches to make it easier: HN could serve every user under the Sun and still be entitled to have a (perfectly legal) rule that says "Don't solicit upvotes". No amount of "oh but at their scale" will change that.
Apple, Google, Facebook, etc. or any company actually do not write laws (they lobby and bribe for them but that's a different can of worms). They just write their own rules for their own products and services. Those rules have to be within the law and even if common sense and current evidence may say they break the law, it's up to a judge in an antitrust lawsuit to decide.
Indeed they don't. And yet they're still not laws which is great for us because those rules or practices can be found illegal.
As I tried to explain above, HN is free to have a rule which says "Don't solicit upvotes" but they can't have a rule "Don't talk to women". The simple answer is because no matter what that rule says, tit's not a law, it's just a rule which can be applied only until a judge decides it's against the law.