That can always be changed in the code to reduce the % or make a finite number of coins.
no that is a bullshit way to run a coin. once those flood gates are open, the project dies.
On this precise topic, we've exchanged some ideas already earlier, most or all of which, would preserve the stake %.
I posted concerning this (along with another feature request) here:
http://forums.dfx.io/index.php?topic=14.0Happy Staking!