I suppose he couldn't "keep the net" because his .920 SV% in the 2nd half of the season was interfering with the tank and Sparks was the better strategic choice with that goal in mind.
Yes, instead of winning games when they were important, he won them when it was meaningless to win.
I thank Bernier because without him there is no Auston Matthews. He was horrible for the first half of the season despite being given the job on a platter. IIRC, if you take out the horrendous start in October, the Leafs were the second/third best Canadian team over 6 months from November to April.
Bernier gave us Matthews as much as Sparks did.