Huh? They gave up what 13 goals in 5 games(and 2 OT's) against Florida? That's not that problematic at all. The problem is their Mackinnon equivalent scoring 0 goals in a 5 game series and only scoring 10 goals in a 5 game series. The defense is fine.
Mikko had 1 goal in the Blues series. He had 0 goals in the Tampa series. But other guys stepped up. Especially on D.
You need offense from your defense in the playoffs, because you can't shut them down, the way you can forwards. They're an X factor. When it's a tight low scoring game, a goal or a big shot or play from a defenseman is often the difference in a game. And all the games in the Leafs-Panthers series were close.
Matthews and Marner not producing was an issue, and I've always thought they're too soft in the playoffs, but teams can win despite their stars not scoring in a round. Happens to star players in at least one round of most deep playoff runs. Teams find a way to shut them down, but a good well rounded team still wins.
The problem is Toronto had no equivalent to the Avs D core to compensate for them getting shut down.
Leafs in 11 Games
Rielly - 4 goals 12 points
Brodie - 0 goals 3 points
McCabe - 0 goals 2 points
Giordando - 0 goals 2 points
Gustaffson - 1 goal 1 point
Holl - 0 goals 1 point
Schenn - 0 goals 1 point
Liljegren - 0 goals 0 points
Avs in 20 Games
Makar - 8 goals 29 points
Toews - 5 goals 15 points
Byram - 0 goals 9 points
Manson - 3 goals 8 points
EJ - 1 goal 5 points
Girard* - 1 goal 3 points