Would this apply to Zimride, Riderbee, Ridejoy, etc. ?
I don't have a strong opinion on how this should turn out and am not an attorney. Rules that limit industry like this are sometimes the result of regulatory capture, but are equally often the result of consumer pressure following malfeasance by unscrupulous service providers some time in the past. Certainly such rules represent an increase in red tape, but that doesn't mean they're inherently bad; one might argue that they're an unavoidable corollary of a complex technological society, reflective of the challenges faced by its members - just as product liability rules are reflective of industrialization's severance of the traditional relationship consumer and producer that used to exist at the local level (blacksmiths, carpenters, et al.).
Incidentally, I hope people won't interpret the CPUC's representatives mention of enforcement mechanisms as a threat. Spokespersons for public bodies like this are duty-bound to cite the way the law actually operates, rather than make policy statements about how it should operate. So discussion of enforcement mechanisms is no more than a restatement of fact in response to journalistic inquiry.