Child Abuse in California

California has now passed a law lifting the statute of limitations on child abuse claims. The law specifically retains the statute of limitations for public schools and other government entities. The government can abuse your children, private citizens cannot.

Why not lift the exclusion for public schools as well?

Here's your answer.
You should especially like this sub-link, where the GAO finds sexual abuse by public schools and subsequent hiding of the abuse to be a NATIONAL problem.

According to a report commissioned by the U.S. Department of Education, in compliance with the 2002 "No Child Left Behind" act signed into law by President Bush, between 6 percent and 10 percent of public school children across the country have been sexually abused or harassed by school employees and teachers.

Here's The Economist on the New York habit of "passing the trash" - covering up teacher sexual abuse, along with the money quote:

A 1995 study of 225 cases in which pupils were sexually abused by teachers or other staff members found that in only 1% of the cases did the school-district superintendent attempt to revoke the culprit's teaching licence.

Education Week ran a six-part story on it in 1998, with an update in 2003.

Here's a DOE synthesis study

That's what I found on Google in 60 seconds.
There is a lot more.
Just google "passing the trash sexual abuse public schools" or "sexual abuse public schools".