Merrith
Pretty much hits the nail on the head. Just the reality of the NHL in the salary cap era, that's why good teams are always quoted as having a "window". Happened to the Kings, currently happening to the Pens, shit with Nylander's new contract they are already starting to talk windows in Toronto. I think complacency also plays a factor which was addressed with Q. Obviously an amazing coach, sometimes you just need a new voice behind the bench.
Also worth noting, winning tends to thin the size and quality of a teams prospect pool and the Hawks are no different. This summer they were ranked 23rd in that department.