This is necessary because there are different grades of programmers. Frankly, some are better than others and social pressures force us to acknowledge it in some way.
It's been this way as long as I remember, one of the first things I was issued at my first programming shop was a chart that enumerated who was an entry-level 'E07', who were mid-level 'E08s and E09s' and who had reached the coveted rank of 'E10'. The groupings will probably be similar no matter where you go, though the titles will change.
I think it's a natural workplace dynamic.