Note that UCs and CSUs do not require any counselor involvement at all at the application stage (no recommendations and no transcripts (applicants self-report courses and grades, to be verified on matriculation)), although they do provide resources for counselors to advise students who have questions on the applications.
Many counselors are overloaded, and not exclusively focused on college matters. Teachers whom students ask for recommendations may also be overloaded, and practice recommendation rationing. Recommendations implicitly advantage students in well resourced high schools where counselors and teachers are less overloaded, so that they have more time to write good recommendations and not practice rationing as much.