I get what you're saying. It's more of a science club. But I think the "fuck you Christians" is kind of the point.
In their opinion, religion shouldn't really have any place in secular public institutions. If we're going to allow Christian Clubs at public schools, we should be ok with any religion having their own school club. Up to and including "Satanism".
It's like a protest or troll "religion". Atheists have done the same thing with "The Church of the Flying Spaghetti Monster". I imagine if Christian groups started staying out of public institutions and the government they'd be fine disbanding changing their name to the science club.
They also do stuff like this.
The Satanic Temple is challenging Indiana’s near-total abortion ban with a lawsuit that claims the ban infringes on their followers’ religious rights and violates the U.S. Constitution.
thehill.com
I think they're nerds. But they're well meaning nerds. And Satanists aren't the ones passing creepy theocratic laws these days. So I'm not wasting any energy being upset with them.