If you don't see your name after a search it would be pointless to have the list as fewer people will use it when their name doesn't appear. I for one would never make the top 10,000 lists as I am not fussed with PvP but the game needs an incentive to strive for especially for the devoted PvP players. The next page will contain the following 100 rankings and so on. Simply divide the top 20 or even the top 10 in a separate table before adding the next table of 80 or 90 to make up the top 100 list. So they might as well list the top 100, 1,000, 500,000 as it makes no difference to the stats count and programming.
However, stats on all players would need to be gathered to be able to find the elite 20 or so. I understand what you are saying and to some degree I can see your point by keeping the list short.