This doesn't really make sense. The existence of other moral systems does not somehow imply that they are justified.

You keep using the word "justified". Can I ask who performs the analysis to arrive at this conclusion whether a moral system is justified? If it is a human being, can another human being not possibly perform the same analysis and arrive at a different conclusion?

In fact it's pretty easy to just artificially construct a moral system that's internally inconsistent and self-contradictory. Also, the fact that the overwhelming majority of moral beliefs result from cultural norms and social constructs don't actually make moral systems inherently related to those things.

You mean like slavery? Like right to live free? The whole issue that although is now recognised as a universal right, was fought over in the past and divided many parts of the world? Or perhaps, colonialization? Or suffrage? Or every thing that people have gone to war over because they believed they were right and others weren't?

I'm not sure what your actual position is here.

If your position is that complaining after willfully making a suboptimal decision annoys you, then okay, fine, nobody has an issue with you being annoyed, that is entirely your prerogative.

If your position is that complaining after willfully making a suboptimal decision somehow diminishes the strength or logical validity of that argument compared to making that complaint before making said decision or without making that decision at all, I'm not sure how that logically makes any sense because the unfairness of the price does not depend on whether or not you personally chose to opt into the scam.

First thing first: It's not a scam. Shops can sell at whatever fucking price they want. I use the word "scam" to portray the feelings of the buyer. But in this case the buyer has the freedom of choice to choose which store to patronize. You don't buy a Bentley then claim the Honda is cheaper and complain to the Bentley dealership. You have the agency to exercise your choice knowing full well the consequences of your action. It's an illogical, irrational decision to make and therefore, the it does diminishes the strength or logical validity of that argument.

My stance is that dismissing complaints just because they were made after breaking the laws is logically invalid. You can say that it is stupid of them to complain, but you cannot, in my opinion, actually dismiss the complaint itself on those grounds.

It's not a complaint really, it's an objection to the punishment meted out. It's like saying "this punishment is not valid, I should not be punished." It's a an attempt to weasel out of the punishment the way I see it.

I'm not sure that the answer to "why" people did these things really matters here. Complaining before or after doesn't change whether or not the application of a particular punishment is morally justifiable.

Once again, it doesn't matter if it's morally justifiable, because no where do I argue about the justifiability of it, as I have stated, I am neither for nor against corporal punishment. They have their pros and cons, just as any punishment would. I am only arguing for the recognition that the punishment is deserved in the eyes of the law and intervening in that, is an attempt to compromise the sovereignty of the nation executing the punishment.