You could, but I don't really see any difference between this and just slapping many tb of unrelated data in the database - the smart attacker will realise that a bunch of accounts are fake and just join to a table that holds only data for real users before extracting the info.

That's part of the elegance (well, it's something other than elegant because it uses a whole mass of data) of the original solution - all of the data could be significant in checking a single password so none can be discarded.