Edit: I found an article with some numbers: http://abovethelaw.com/2016/11/californias-bar-exam-passage-...
The breakout chart (towards the end) shows that ABA-accredited school graduates passed with a rate of about 60% on the first try, which seems alright, compared to a dismal 30% or less for unaccredited schools.
Edit 2: For comparison, the NY bar passed 67% of first timers, which is a little easier than California, but not dramatically so. Source: https://www.nybarexam.org/ExamStats/2016_NY_Bar_Exam_PassRat...