Well, is it true that he maintained the existing private parking access, as the previous owners had done, for the first couple years he owned it? Is it true the commission was trying to make him operate a business at a loss?
As for the private beach argument, is there any evidence to support this? He doesn't reside on the property. Is there a history of him hosting private beach parties? (According to him, the previous owners did this at times.)
If the coastal commission has really been that overreaching, which sounds entirely plausible, then what's wrong with fighting something on principle? It doesn't really matter that he's spent more fighting this than he would have in operating a parking business at a loss. It's the principle of the matter. He's a billionaire, so he can afford to fight this. If he doesn't fight this, what happens to the next owner of much lesser means who can't afford to fight it? Are they just supposed to accept overreach of a governmental commission without recourse?
I do agree with msethhunter that the court needs to mandate a solution. Normally, I'd think that would be a government maintained easement or eminent domain purchase of an access road and parking/facilities through the private property. If this particular piece of property has some pre-California Mexican property rights or some such unique roadblock, then maybe nothing can be done.