Chance Linkage is the Main Source of Change in Human Genes

I have not really being paying attention to the discussion of the paper Recent Acceleration of Human Adaptive Evolution by John Hawkes et al.  However, I was struck by this which comes at the end of one of Hawkes' blog posts about the paper:

... the most widespread source of change in human genes is chance linkage to a relatively small number of selected sites.

That is, most of the genes that have changed in recent human evolution have done so, not because they were beneficial, but because they were located on a chromosome near to a gene that was beneficial.  This seems to me to be quite an important point.  I think I might go back and read the original paper.