I'm nearly completly baffled by the OP.

Can't find a place to go backpacking in California?? Seriously??
There are literally tens of millions of acres of designated wilderness area, BLM land, FS land and National parks in California, I honestly don't understand what your issue is.

To bluntly answer the question that is your thread title. No, it's not. Your entire premise is completely backwards. There are more people getting out into the backcountry now then there probably ever has been. It kind of ticks me off because some of my favorite places where I used to not see another soul for a whole week trip, and now getting too crowded for my liking.
Wyoming's Wind River range or western Montanda has a lot of backwoods trails that you would go 3-5 miles.
That wins the understatement of the month award right there

. I worked as a backpacking/climbing guide in the Wind Rivers for 6 straight summers, I kind of consider the Wind River backcountry my second home. There is easily over a thousand miles of trail just in the Winds alone, and humongous tracts of pristine trail less areas as well. I say if you're not going at least 10 miles from any parking lot/trailhead then it's not really camping. Personally I like to go off trail as often as possibly too, just to get away from as many people as possible, I've hiked to lakes and peaks in the Winds that are many miles from any trail... not that I recommend that to a novice...