Isn't AU-58 better than AU-50?

This topic has been bothering me for a while. Since NGC, PCGS and ANACS all grade AU coins with at least 4 levels (50, 53, 55 and 58), shouldn't regsitry scores reflect this. And also in VF and EF, they throu in 25, 35 and 45.

So shouldn't someone who paid extra for a higher grade receive more points??? To me, it's the same as for the MS grades, a 63 will get less points than a 64 and so on. I can understand for modern coins (but to be fair, all should be treated equally), that with modern methods, there's probably not as big difference in the grades. But for older coins, I really think it's unfair to give the same amount of points for an AU-58 and an AU-50.

What does everyone else think?? And NGC, can you respond with an argument against???

2Cent1869o