Separation of church and state, especially when schools don’t allow alternative books (eg in some Bible Belt areas). Also, the bible does have violence, sex (including rape and incest), etc.
I understand there are reasons it could be banned, but I'm saying that in reality it is not. It is widely available in elementary and middle school libraries.
There have been many attempts to ban it, but a backlash usually results in its reinstatement. IIRC there are often cases where questionable verses are blotted out or it's only the new testament (which is in general less "graphic"), but it really depends on the jurisdiction.
Except for one case in Texas that made a splash in the news last year, I didn't find other cases of the Bible being banned from school libraries. Did I miss something?
If not, it would make sense that Texas made the news because it's out of the ordinary.