Additionally, it's that managers are also supposed to carry more responsibility, if they make a decision and tell the coder to "no, do it like this", it should be their neck on the line if it turned out to be the wrong decision.

Even though it doesn't always turn out that way, just appearing to carry the burden of responsibility is often enough to make justifications for being paid more.

In reality, the truth is of course somewhere in between the optimistic first paragraph and the cynical second.