It might be true that you are only 10 times better than the guy sitting next to you because he is 10 times worse than you, but this is something of a red herring. There are plenty of terrible programmers out there who are 10 times worse than me. Do I get paid 10x more than them? Not even close. This article is more about why a 10x productivity increase does not equate to a 10x pay increase than it is about the possible existence of programmers who are 100s, 1000s, or 10,000s times better than the worst possible programmer.
Try time the clerks in your local supermarket, I am sure you can find one which is twice as fast as the slowest, should he or she get twice the salary?
When it comes to programming there are relatively many bad programmers hired (on a base salary). Maybe the good programmers are underpaid, but definitely the bad programmers are overpaid.
Anecdotal evidence also suggests that programmers are generally bad at negotiating their own salary.
