Krueger won five straight championships as a coach in Austria, plus two international club competitions in Europe (against competition from Russia, Sweden, etc.), before turning Switzerland from cellar-dweller that moved between the A- and B-championships into the best nation behind the top-teams, completely outmatching the competition for that spot in terms of play. This included beating Canada in the best-on-best 2006 Olympics (with a shutout to boot) and only losing to Canada in a shootout in the 2010 Olympics.
He may not have worked out as a coach in the NHL during the short time he was there, but claiming that he "can't coach for shit" is completely asinine. He was the epitome of a coach who could turn a team into a close-knit unit that played far above what seemed possible for 95% of his career.
As for Woodcroft:
I wouldn't spend too much time worrying about what didn't work out last time around. Coaches don't always stay the same. Sullivan looked like a complete tire-fire in Boston, to the point that everyone thought you would never see him in the NHL again. Then he spend some time in the AHL, returned to the NHL, and won two straight Cups. Coaches can change. Paul Maurice didn't really look like a future Stanley Cup winner for most of his career either. Doesn't mean that Woodcroft will change for the better, he could also carry the same flaws wherever he goes, but I wouldn't assume that it has to be the case just because he had those flaws the one time he coached in the NHL.