Both sides have valid points, there is no easy solution. I certainly appreciate not wanting to drive many hours and get turned away. I have also noticed less available facilities over the years. My camping style has also changed. When I was a kid we had a VW Westfalia, and after I grew up I camped out of the back of my truck for many years. No need to worry about site length or being level like I do now, even with a 22ft trailer.
I just am not sure why they felt the need for it at Cachuma. There was no mass of campers at the gates Friday trying to get a site, and we often saw several empty sites around us the whole weekend. But now that they can be reserved, they fill up, and I am not willing to chance the remaining handful of walk in sites (10% is not an exaduration). And Cachuma is a county park at that! I recently stayed at a Ventura County park and was pleased.