For the UC system, including Berkeley and UCLA, GCs do not provide any sort of letter or report as part of the application process. In fact, transcripts are self-reported by the students applying, and are not sent by the schools until the summer after HS. So, GCs in CA don’t necessarily get to know their students, especially those not applying beyond the UC/CSU system. And, many GCs in CA are likely less-practiced at writing LoRs, school profiles, etc.
The UC application, which doesn’t use the Common App, also asks about the highest level of education completed by each parent, but not about what colleges the parents attended.