Most people, nomads or otherwise, won't tell everybody that they earn a lot of money. 10k a month is considered a huge income once you get off the taxes and costs of living in your own country.
A nice % of nomads are relatively low-budget, as it as very good lifestyle (perhaps the best one?) for those that don't earn huge incomes for whatever reason.
Rich nomads are not that plenty, and they might be scattered around the globe, and most likely in cities such as Hong Kong, New York, Tokyo, Paris or that kind of places. At least, that's where I met the few I know.
I think that the issue here is that there are not enough rich nomads, those that exist not necessarily are in touch with each other, and the world is just too big to have them all in one place. I've met different nomads, and almost no one was rich.
I have the feeling that the nomadism impulses end quite easily when people start making seven figures.
In our case, we make enough money to spend all year long on the road, but we prefer to get back home for 4 or 5 months to put everything in order before we depart again. To each his own, of course.