"fair" is subjective.  In my opinion, a 100% pre-mined coin is fair.  The creator of such a cryptocurrency has the best claim to the coins.  No-one is forced to buy any of them from him.

Rather than lament the absence of a cryptocurrency with an initially uniform distribution across all 7.3 billion people on this planet, I appreciate the incredible amount of work, resources, risk, and patience that many have put into these projects.  That I am free to join or leave any of these projects at will is already more than fair as far as I'm concerned.

The key disadvantage of a fully equal initial distribution is that it would be unstable.  Some people would be keen to acquire more while many others would not care at all about their coins.  Market volatility akin to a violent chemical reaction would ensue, ultimately resulting in a Pareto distribution.