Nope, I really liked it.
I liked the rest too, though.
The ending image you posted is what made the finale for me--as a callback to the tree Jack showed Ashi in Aku's wasteland, except now surrounded by life instead of death, was a cool bittersweet conclusion to her story and an indicator of what her sacrifice accomplished.
Also, Jack expressed sadness that he thought he'd never see the beauty of his former world again, and the idea that she (and everyone else) was willing to sacrifice themselves to make his world beautiful again was something I found really romantic.
I won't say it was perfect, but I was able to enjoy it.