Not sure what your particular experience was, but dispersed free camping has been the norm here for quite some time. Halfway, Thuderbird and The Flume (just below hospital flat) are all decent spots. A campfire permit is required. There is some information at the following site
Sequoia National Forest - USDA Forest Service - Upper Kern River
also a quote lifted from another site...
DISPERSED CAMPING AREAS -
Along the Upper Kern Canyon there are dispersed camping areas, free of charge, which are great for campers with self-contained units or large groups of people. Campfire permits are required
when camping in these areas and reservations are not accepted. However, camping and the use of campfires are not permitted within 25 feet of the river's edge, streams or trails.
Chemical toilets and trash receptacles are provided in most of these areas for your convenience. We ask that you please use them. In areas that do not provide these services, PACK OUT WHAT YOU PACK I
Especially, diapers, toilet paper, and human waste.