They added the historical context of the Rosa Parks story, but to say they're being critical just isn't true.

It’s true that kindergartners may not understand the more nuanced historical details like the fact that Parks wasn’t just a tired woman on a bus who made a spur-of-the-moment decision, as many believe. She was a longtime activist and had planned the act of civil disobedience.

They're excusing her gross oversimplification of history. The rest of the article is saying what she did is a good thing, and they only include quotes of praise:

People thought Slater’s lesson was great.

“Someone give this woman a raise,” a person commented.

“I would’ve loved you as a kid,” someone said.

“This is a perfect way to show them,” another wrote.