YACoin is the fairest coin ever. People are able to mine it even now with a higher reward per block than the early adopters. I guess the best criticism of YACoin is that it really screwed the early adopters--particularly compared to other coins.
It was/is extremly fair compared to others.
I don't belive it's fair for a few early adopters to make huge amounts of money for just beeing at the right place and time. Since YAC prices crashed after launch everyone regardless skills/timing/equipment could buy that amount of YAC he wanted to buy. Everyone without a mining rig or expensive ASICs can mine so even if you weren't capable to spend a few bugs on YAC you could still get some for free.
This used to be the same on bitcoin, but only if you were damm early to the party. For YAC I belive people will still profit from buying into it a few decades from now while on bitcoin everyone that buys in a few years will get screwed hard. If you haven't got any bitcoins by then you will have to pay enormous prices and have the risk that noone will buy at the same insane prices you bought. PoW keeps YAC sane while on BTC it doesn't matter anymore.