He would have taken the Pittsburgh job way over the Ottawa one. More money involved and a lot more prestige. The teams obviously are a different trends but it's not like he took an impossible task. I think a lot of the Pens issues isn't just because they are older.
He spent roughly 25M of the cap space on Smith, Karlsson, Graves and Jarry, and signed a ton of depth players in hopes of finding a gem, and now added Puljujarvi. Jarry has been pretty good lately, Karlsson is as advertised... but the rest have been pretty iffy. It's just a weirdly constructed team at this time. They had plenty of money and assets to play around and retool the team back into contention, but a lot of the moves haven't worked out.