That is an interesting idea. Could a current big pile holder mint everything if his coin piles were distributed into nice piles that would equal the number of POS blocks for 1 day (or 3 days or 9 days, why not) and prevent smaller holders from minting regardless of their coin age and accounting for randomness? If possible (not sure it is) there would be no advantage to maintain the piles (50%/year) and eventually the piles would be broke down into the same small piles competing against other small piles with coin age and randomness being the deciding factor.
In the end (if your concern is true) we would still be where we are right now but new holders and maybe even potential dumpers would see the joy of POS and stick around.
Interesting thought experiment if nothing else.
in former post i decribed vulnerability of pure pos coins with big gap between min age max age
regarding the theory u have about big wallets can have a advantage by try mint more blocks
the answer is it doesnt work and it would give no advantage
u cant get more pos rewards because u able mint more blocks.....
the rewards always deepend on coin-age
and there is no way to manipulate that
look at blockexplorer whats the average coin pile size and age that successfull create a POS block
its now like 10 days and 10 dmd pile size
so in fact its easyer now for small DMD investors to mint their coins then before
u can expect that this values will change a bit over time
i expect it will be like average time to mint 15-20 days and average pile size 5-20 dmd
there will be some coin pile that stake after 30 days and merge together to a above 100 dmd coin pile
once this happens the network is full adapted to the new POS settings