That's how all crypto currencies are they are using the same formula. Right now we aren't looking at the death of Cryptocurrencies heck not even BTC for that matter. What we are looking at is how Economies work. When mining payouts halve and difficulty increases people stop mining. The BTC we have now becomes valuable. However people will lose faith in BTC which then may turn into its death. Dramatic shit.
In short you can't have a stable cryptocurrency.
Nah, we won't loose faith in cryptocurrency. I mean, it may become the new "cash", as it's hard to track.