In the future, if I see a kiter who I deem a threat to his own safety, I am going to politely approach this kiter and talk with him. I have done this since day one.
Before I approach him, I usually look for 2 other kiters that I believe have the same thought process as myself and ask them to help with the "safety speech" to persuade the rider not to ride, to take lessons, (whatever that scenario holds).
I know a few who I can depend on (including Raul, Tom, Steve S., Scott W., Toby and others) to tactfully help in this type of scenario. Steve S. noticed a total novice about a year ago at the backside, asked me to help him "give the speech" and we helped stop a problem before it happened in a very positive manner thanks to his observation and actions.

Anyone who believes in this approach of politely policing our spots, just tell Raul, me, Steve etc. next time out. We will eventually have a group of responsible riders that cooperate and in a tactful and civil manner assure continued access to our spots.

This isn't a gestapo statement, btw, pretty far from it. I don't foresee shutting down every newb out there or doing a full body search prior to riding. That's not what this is about. It's about shutting down the totally incompetent rider quickly and effectively before they end up embedded in the side of a truck with their kite headed toward the interstate.
It's easy enough to spot them most of the time. The thing is, often decisions have to be made very quickly after the rider's clueless-ness is determined. (b/c it is often not obvious until they go to launch improperly or crash the kite 4 times in a row right near shore immediately after launching) etc.

It'd be nice to know very quickly when responding to these scenarios who we can depend on to "jump in" and help quickly by just yelling their name and knowing they are going to follow your lead and help (kind of like who is on the volunteer fire fighters squad or something) as opposed to having them question your actions.
Helpers would be helping secure the person, the kite and then help with a polite but firm speech. This, imo, should never approach anything close to a fight or intimidation. At the same time though, I can tell you from personal experience that giving the "speech" alone while others sit and watch passively is moderately ineffective without raising your voice and acting aggressive for some, because some interpret the apathy of other kiters as indicating that the one guy giving the speech is some kind of safety whack job with extreme views that aren't agreed upon among the group.

Anyway, if you think you would be interested in helping out, just approach me next time out there and we will begin to get a group of friendly but persuasive helpers as an alternative to suicide by kite. I hope this scenario only happens 3 to 10 times all season. It'd be nice if we successfully responded to each one before a possibly bad outcome. In the past we have been a little lax, imo, about stopping a problem before it happens.

If you don't want to be involved, no worries, just don't volunteer.