Y'know, I'm not all that worried that it makes kids more anxious. That's just a realization that actions have consequences. However, I must admit that I find the part about it promoting misbehavior strange. I guess it could mean that some kids are purposefully trying to get kicked out of school or that ones who make stupid mistakes (Bobby made a peanut butter sandwich and accidently set the butter knife in his lunch pale) will try to hide them rather than owning up.
Don't get me wrong, I think zero tolerance policies are overbroad and lazy. If a school treats the kid who brings crack and the kid who brings aspirin to school the same it's a school which is failing to be responsible. That said, the few times I've had dealings with this sort of thing I've seen a lot of common sense applied under the table. High school principals don't want to throw out a kid who accidently puts the butter knife in his lunch tin after he makes his PB&J sandwich for school. Just as long as there isn't a lot of publicity about it they are willing to use their common sense.