Long story short, Sark inherited a 4-5 win team (that everyone said was a true 0-12 team), got a little bit better the first season then flatlined for 3 years. Wilcox helped but struggled badly against the best teams. Last seasons squad had top 10 talent and underachieved. Sark gets a ton of credit for the turnaround when he did very little. Off the field he was late for meetings, a drunkard, cheated on his wife all the time, verbally embarrassed himself and the school, blamed a message board for his recruiting failures, etc. Meanwhile, the local media, led by Dawgman.com stifled any dissent and questioning of Sark, instead proclaiming him as some great turnaround specialist. He had top 20 talent yet never came close to competing for a conference title.
After the 2011 season Sark fired more than half the staff to save himself, then got a "blank check" from the school to hire top assistants including Tosh Lupoi who secured players like Shaq and John Ross who otherwise wouldn't really have considered UW.
Last year's offense had the best tailback in the nation, best TE in the nation, experienced OL, QB with 2nd best rating in pac-12 and a ridiculous amount of talent at WR (3 or 4 NFL guys) yet wasn't even top 20 nationally in the key offensive stats.
You are dead on with Petersen. If he was hired a few years ago, last years squad may have been a NC contender. He is clearly the best coach in the conference and there is a very good chance he will be here a long time.
Will Dissly is awesome btw.