I don't understand the whole "well known" idea of a 10x productivity difference between best and worst programmers. It gets even more confusing when he claims t

I don't understand the whole "well known" idea of a 10x productivity difference between best and worst programmers. It gets even more confusing when he claims that some developers have negative productivity. Maybe the productivity difference is -10x. One really great programmer can overcome the damage done by 10 awful programmers. Or maybe we can just not pretend that programmer productivity can be described with numbers at all.