My thought is that POW coins are increasingly difficult to mine. Most new coins WILL be from POS. Those who mined early and hold a huge load of PPCs are getting most of the new coins. If you just hold your PPC and not spend it, you will own an increading percentage of PPC money base because of compound interest (i.e. newly minted POS coins will mint new POS coins). So the rich will become richer.
I never did PoW, and doing PoS now with a quite number of coins, that I have bought rather cheap, I believe.
I see the 1% interest for PoS as a very reasonable supplement for lost coins, this stabilizing the price of the coins a little bit.
Regarding the fluctuations in value of this coins, for buying interest somebody needs to wait on a price drop of 10%, to earn the same as for PoS minting after 10 years.