The low four year graduation rates probably have a lot to do with the relatively low admission selectivity of many CSUs, and the significant population of part-time students and students taking course loads at the low end of “full-time” (i.e. 12 units per semester instead of 15-16 units per semester) due to work or other non-school obligations. Some CSUs (though not Sacramento or San Jose) do have four year graduation pledges (e.g. https://www.cpp.edu/~academic-programs/graduation-pledge/4yr_Graduation_Pledge.shtml ), but their four year graduation rates are still low.