It is easy to get riled up. But note the stories cover the whole planet and go back to 1997. It
does happen, and where it happens it is nasty bureaucraps taking advantage just to be mean. But any given kid is more likely to be hit by lighting than hammered by a zero tolerance ruling.
That said, the real problem is the "atmosphere" of fear and oppression this communicates. It teachs some kids to be weasals who can turn in other kids, and it teaches other kids that it is okay to break the rules (because the rules are, after all, so obviously stupid) - and of course, that adults are not to be trusted since it is the adults that passed and enforce the stupid rules.
"That said, the real problem is the 'atmosphere' of fear and oppression this communicates."
Au contraire.
AFAIAC, this is the only redeeming feature of the maniavcal Zero Tolerance policy.
It's a clear demonstration to the kids that the Establishment means them no good; that'll help keep their minds straight When It's Time.
;^)