Dubas did not need to give up a 1st to unload Marleau. He could have done what he did the very next summer/fall and trade Kapanen and Johnsson while keeping his 1st and letting Marleau's contract run out.
Even if he gets a lesser return for Kapanen the assets from that along with the Leafs 1st beat out the Pittsburgh 1st which was the only decent thing they got from both Kapanen and Johnsson. He probably also gets more for Johnsson as well, as Andreas tanked his value the season prior to being traded.
Lou's bad moves don't somehow make Dubas' any better. Lou messed up in signing Marleau for 3 years and not signing Nylander the summer he was eligible for an extension.
Dubas messed up by screwing up the entirety of the Nylander negotiations which set the plate for Marner and Matthews knowing he would give in, and then betting against both Matthews and Marner the summers they could have gotten an extension. He's bled picks since, most notably the Marleau and Foligno 1sts.
He's gutted the depth, namely Kadri, Kapanen, and Johnsson and is left with a middle 1st prospect and Kerfoot.
Shanahan isn't without fault either. He messed up in allowing a GM succession plan to take place during a franchise altering year (3 of the best young players in decades needing new contracts and JT being a free agent.)
Dubas has been extremely underwhelming in his tenure and considering the talent he started with and the lack of success in the playoffs, his tenure so far has been a complete and utter failure. Fans would be more forgiving of Dubas just moving back 13 spots if he hadn't already punted so many trades and picks.
I want the Leafs to win I couldn't care less if it's under Lou, Dubas, Babcock, JFJ, or Ron Wilson. Just win.
I hope for all Leafs fans he makes the right call with whatever goalie he chooses this summer.