Judging by the article, beach is only accessible through private road, dude bought the property containing the road and closed the road. Perfectly within his rights. And this rhetoric about "billionaire putting a strain on a state agency" is laughable.
Yep (well, maybe, I don't really know. But for the sake of argument: Yep). But dick moves are the type of thing that cause bounds of rights to be changed.
We're not lawyers here (or are, and are already aware that we're not before a court). In a conversation of what actions are tolerable to a society, laws can be changed. Without going on pedantic tangents about this or that, I just want to point out that: in general appealing to the law without making a case for the law looks like circular reasoning because changing the law (or using other, existing, laws to alleviate problems caused by the first one) is within scope of the conversation. That's probably why your post is currently gray.
I can't argue with the perfectly within his rights part, but why is the later issue 'laughable?' It's not rhetoric. It's a matter of fact and not opinion that state agencies have limited resources. I don't have their legal budget at my disposal, but I would take a bet that it's less than his.
Because they wouldn't blink an eye and strongarm a small business or individual that don't have legal budget. They even hint at it when "we were surprised he didn't settle since he has to come to us for permits anyway". Now that opponent actually has legal budget, they play the victim and "oh, now, this fight that is actually within our legal framework is not fair!"
If your property blocks access to another's property, you have to give up a slice of your land to provide access for the other property's owner. You can't simply buy up all the land around a property and then close off access. This is called an easement.
In this case the other property is the beach, which is owned by the government, no different than any other property. Khosla has no right to deny access to this property just because his home abuts it. The only issue here is an obscure treaty, apparently, but that will sort itself out.
Good point, some things are not completely clear though - there is still access by water, and since they own all coastland, by definition they have access through their own property.