6 months ago Sharkcoin was worth ($3) and the mining revenue for quark was over 1BTC/GHASH (1000% higher than today)

http://coinmarketcap.com/currencies/sharkcoin/

Today the sharkcoin is worth $ 0.08 with a 24hours turnover of 455 BTC / $ 181,009

When the etherum budget is used, and the coin goes POS the same thing could happen.
Etherum is a new coin.. You can only mine it for another 4 months.