I mean...yeah?
I'm disagree with making a kid write that, and many of the "let's just gloss over the recent brutality and inherent human rights issues with Islam" that much of America loves, but that actually seems pretty legit.
I strongly doubt that the school district actually intended mass conversions of the populace. It's much more plausible that this lesson was the same kind of annoying Social Justice claptrap they put everywhere else they can shoehorn it in. So it's bullshit, and commie, but it's a secular purpose, which would seem to fit:
So long as the proffered secular purpose is “genuine, not a sham, and not merely secondary to a religious objective,” that purpose will satisfy Lemon’s first prong.
Unless your argument is that the case law is wrong? Or the quoted portion of the decision misapplies that law? I confess I'm not well schooled in this particular area of law.
And I'm actually pretty prejudiced against Muslims. I think, after not insignificant exposure to it as it is practiced in Southwest Asia, that Islam is a pretty horrible belief set, and folks that practice it and I don't share many common values.