Robin Hood stole from the rich to give to the poor, but it was still stealing. A lot of times there’s context. There’s also social context. Everything you said is based on your upbringing in your society. No the things you said are always wrong aren’t always wrong. Right and wrong are social constructs. As situations change, right and wrong changes. But this isn’t about philosophy anyway.
Ethics is philosophy. Our fundamental philosophical differences are what prevent us from having any meaningful conversation about RNG boxes. It’s what leads these forums to devolve into shouting matches, where whoever can restate their position with the most force wins the argument; when that doesn’t work, people turn to darker methods. This is what happens when all that’s left are opinions rather than objective standards. MacIntyre wins again.
Or we could just go around and round like this: It’s your opinion that right and wrong are social constructs. Lots of people disagree with you. Your opinion doesn’t make it so. (See how easy that is.)
What I find most interesting is that you are arguing there are times when it is completely acceptable for a company to oppress the poor (or in the case of AreanNet, the mathematically ignorant) in order to make a profit.
It’s not completely okay for Anet to oppress the poor. Nor is Anet responsible for educating the masses. We’ve designed a culture where, at this point in time, no MMO can exist without either A) charging a monthly fee 
having some kind of cash shop that takes in a lot of money
There are two ways to do that with a cash shop. One way is to make it pay to win the other way is to do stuff like the RNG boxes. I sure don’t know any game that doesn’t do either. Unless they sell content, like Lotro does. You can’t do this area and this area, because you haven’t bought them. Which means calling the game free to play becomes a misnomer. Well it’s free to play part of it, but we have this roped off pay only area here.
So it’s not free to play. Well yes it is..you can play all you want right in this zone.
Is that morally okay? Why call a game free to play if you have to buy character classes that are popular or more powerful? To me that’s worse than what Guild Wars 2 is doing.
The only option besides not charging a fee or not having a cash shop that makes money is to not make an MMO at all.
MMOs, for better or worse, are big business these days. I didn’t ask for this setup. I don’t like this setup, but it’s the setup that exists. So Anet has choices, but all the choices it has has to fall somewhere into this setup.
That’s the realism of the matter as I see it. Anet isn’t forcing anyone to buy boxes. If people are stupid enough to buy them, or choose to support the company that way, I can live with it.
Mind you, I’m not happy living with it, but I’d rather see this than P2W or having to buy each section of the game as it comes out.