Yes, that may happen if there's a low amount players who will take advantage of it where low amount players could also be able to mine tokens and devalue the token at much fast rates as you have said. Of course, this does not include those low amount players that doesn't do this kind of thing and only play without cheating or abusing the system. We really can't help if some people are like that because it is the same as greed where it's in human nature.
I highly agree with your point! There're always going to be those type of people who will try to abuse the system and no one can change those type of people as such type of deceiving is implemented in their sub-conscious mind and that's why it's almost impossible to change them. However, it's always better to have some type of system to stop such type of frauds.
Low amount players who aren't frauds but can't afford to deposit high amount of money will at least take some benefits as the later ones, the frauds will always try to do something to disrupt the system and that can't be changed.