No one is so stupid that they want us to call Bitcoin the most, if any, people who are liars. Because when someone is holding Bitcoin a lot they will never tell others because they will be in the reach of the bandits and hackers.
I'm sure that there are various ways to find out about how much bitcoin people hold; however, as many posters already mentioned, there seems to have been a considerable change in practice, especially compared with the early days of bitcoin, and it would be quite rare for individuals to keep bitcoins in a small number of addresses. It could also be less and less prudent for exchanges to keep bitcoin in only a few addresses. So in the end, large holders are likely to embark in a practice of spreading out their bitcoins, and how much they spread it out may depend on a variety of their own personal circumstances, and maybe even some coincidences (which might also contribute to some reluctance to move some of the coins very much once they are already in a seemingly secure location).
Of course, on the other hand, there seem to be developments in both direction. One set of development seems to be attempting to connect addresses to one another in order to attempt to figure out possible common ownership, and another development direction seems to be providing more and more tools to be able to allow disconnection or reannonymizing some addresses.
