How is it way overblown? In any other town, if a GM went 20 years with zero championship game appearances, that guy would have been fired a long time ago or the fans would have revolted that he kept his job that long.
Jerry is the President, the GM, the God of Cowboys football. Every mistake, every failed season, every bad decision, it's all on him. He demanded the power and now you can't make excuses for him when the continually fail to meet any real expectations. When you look at the last two decades, the Cowboys rank amongst the worst teams in the NFL in terms of playoff wins, etc.
Unfortunately, as long as Jerry (and Stephen) operate like they are quality GMs, this franchise will just continue the up and down but largely unsuccessful pattern we have seen for 20+ years.