While I don't believe I have a "right" to know what you earn. I believe even more I don't have a "right" to earn what you earn without your skills and experience mix and role.
Even if we had the same role, I wouldn't believe that, because there's no way we could possibly have the same skills and experience mix.

So to say I deserve as much as you for what you do, is to say to say the reverse is also true. That takes all my meagre ability and the enormous effort I've put into honing it and throws it directly in the bin. If you stepped into my role and still did better than me, that's simply proof that I'm not as good as I think I am, not that you are not as good as they think you are....
The latter is a cop out, it's I don't like this game, I'm taking my ball home.
It's waaaah, it's not fair.