Broken POS is not a good feature or anything like it. Basically all it means is that the coin was so hastily coded that one of the primary aspects of the currency doesn't work right, and what's more it still hasn't been fixed (even though it's been a known problem for more than a month now). Why does this matter? Well, if there's no intrinsic reward for holding PIGGY (e.g. you don't actually get any noteworthy increase in holdings due to staking), the only thing that can possibly drive the price up is people wanting in. But why would they want in on a coin where the 15% PoS is broken -- e.g. if PoS interest is broken, what else might break?
It's not too bad. Dev says the interest will rise to 15% over the course of a year. We'd need a hard fork to change that, so maybe better just to wait and let it be.
(15% is a little too much in my opinion anyway, but it would require a hard fork to change that too.)