K's most certainly are a detriment to scoring runs, just other things like OBP and SLG can easily outweigh them. The Brewers do strike out too much and they don't BB enough, but they hit for enough power to offset a lot of the problem. If you took the Brewers and left them with the same exact power and same exact BB rate and somehow magically made them strike out 0 times they would be a much better hitting team. Obviously that is not realistic but you get the idea.