Back to the original question: Why do kite surfers think that all kiters want to go on the water?

Why wouldn't they? Kite surfing is obviously a blast and if you like kiting, why wouldn't you want to go on the water?
That said, I do think it's strange how few kiters at my home spots ever try landboarding or snow kiting. (no buggy for me)

Everyone in the kite surfing crowd is politely interested when I talk about landboarding, but few of them are interested enough to try it in really good wind. Most think it's nuts to think of doing jumps on a landboard, or flying a 12m kite on dry land.

Many people think that kite surfing is the pinnacle of the kiting sports, and maybe it is. Here in Ontario, the best wind, best surface conditions and all around most consistently good conditions are found on the water. Sad but true.

For me, ultimately, the best ride, is today's ride, land, snow or water. (But i'd take a 12" of fresh powder if I had my choice).

Off to my landboard this afternoon.
Ontario Map
LocalKiteSpots - Milliken Mills

I get the same question all the time from new kiteboarders on our beach when they see me tooling around in the buggy. For me it's just a bit more awkward. I have a heart condition that, under certain circumstances, can limit blood flow to my lungs, which causes me to loose my breath and strength all at once for a minute or so. I am at no greater risk than anyone for biting the Big One, but I'd be in trouble in the open water if I had to be motionless for a minute. Now that I have mapped out in my mind how much of our water is at waist or chest deep at certain tidal ranges, and have found a Mystic Flotation vest cut to fit with harnesses, I'll likely give it a try soon. Until then I just keep telling people that I prefer to keep my arse dry (while I sweat like a pig in the hot GA sun).

I agree with Phillip (and many others) here. I'm working on water skills but still jones for feeling the pull in my buggy all the time. I don't feel like there is an ultimate kite activity, but see myself continuing to try new and different things. Each one I learn has a synergistic effect on the other things I do and plan to do in the future. I love harnessing the wind and having it power some fun. I do like being able to check the boxes now about having kites I can take on the water and that I am able to kitesurf (at some level). I don't feel like kitesurfing is a pinnacle of the kite sports but yet adds credibility to the buggy side of things because "yes I can kite surf but this is a blast as well".