70% is too high a dominance for Bitcoin. It is good for Bitcoin HODLers but definitely bad for the altcoins fans. If Bitcoin's dominance will fall to the 60% level, that is still going to be high if we what we wanted to see are strong waves of green from the altcoins. Bitcoin will have to settle down to around 50% dominance for a great deal of altcoin recovery. Even then, only strong altcoins will make gains. The shitcoins will remain shitcoins despite the increase of altcoin percentage of the total market value.