Welcome to my home state. 
Patrick, while the South Carolina memorial mostly strikes me as a waste of funds (by the donating group) and an example of poor judgment all around, I find this state law far more disturbing:
I’ve never been a fan of “In God We Trust” on coins and currency. It expresses a false claim: that somehow our government (and society in general) trusts in God. Moreover, Jesus certainly didn’t encourage external displays of piety for all to see.
No, it makes the true claim that the God people trust is The Almighty Dollar.
I agree with your main point – I see it as unChristian. Yet it is groups that call themselves “Christian” who insist on it.
The group, called Working to Initiate Societal Equality (WISE), suggested that the district display a different version of the message that includes Buddha, Yahweh, Allah, science and the spirits.
What kind of spirits? Maybe I can get on board with this
In Pasta We Trust
Ramen
Would it be okay if some schools put up signs “In Allah we Trust?”
No doubt the supporters of such state laws would reply, “That’s not the official motto of the United States of America.”
I think it was Florida which tried to pass a similar law about “In God We Trust” signs but it failed in that state’s Senate. I assume we will be seeing more such laws, especially across the Bible Belt.