More currencies create a fiercer competition. I think a young market needs that energy to survive. 
Not to mention the fact that with more currencies in the mix we have more incentive for creativity and innovation. We see copy and paste nature of the tech behind several coins and the people quickly reject them, which in turn provides the developers an incentive to come up with better solutions and more innovative approaches to existing issues. 
I mean we can take a look at the  basic level POW to POS to Delegated POS and beyond. This kinds of provides a perspective of how this free market is evolving. Developers know that evolution is all about survival of the fittest and thus they push themselves for getting better. 
In the end if we remain committed to the idea of a truly free market, this race for a better product could in fact actually be a blessing.