Personally I think it'd be a pretty big distraction if everyone knew exactly how much everyone else made. I don't really care to know what the head of accounting is making, or what the customer support lead is making. If the company needs someone with a super-specialized skill and has to pay them 3x what I'm being paid, what business is it of mine?
If the company needed my skills desperately and I was offered 3x the salary that a current new hire is getting, I don't see how that's helping or hurting anyone else. If anything, I think knowing about it would lead to other company issues that are just a distraction from the overall business.
Salary information is public knowledge in several countries, and even in the US, government salaries are public.
That experience shows that this information does not cause a big distraction.
Public salary helps level the power imbalance between the employer (who has more experience in negotiation and more knowledge about what people are willing to accept) and the employee, and makes it harder to hide systemic wage discrimination.
You do not care about the salary of the head of accounting, and that's fine (though it doesn't hurt to know). But you should care how much your buddies and other people in similar positions are being paid. Otherwise, how do you know if you aren't being short-changed? You'd be surprised.
If the company needed my skills desperately and I was offered 3x the salary that a current new hire is getting, I don't see how that's helping or hurting anyone else. If anything, I think knowing about it would lead to other company issues that are just a distraction from the overall business.