Even if the increased mining difficulty would ensure you'd get 20 ART a day in the first years, there's still not al lot of incentive to invest IMO, as we hardly have any idea about the price per coin, and the exchanges it will be listed on. The great thing about the cryptomarket is that prices can climb with 1000% in a matter of weeks, yet with a genesis address and a fixed mining amount, that advantage becomes worthless. Hopefully, we'll be able to buy ART in bulk up front like minereum, otherwise it'd take years for an investor to break even, let alone make a profit from buying a genesis address.