from a logical standpoint, cloners need a reason to clone: the only reason for a clone to become successful is that the initial distribution is horrible. if everyone agrees that the distribution is fine, the clone will never get support.

this argument even holds from an empirical standpoint: see nxt, which was closed source until the mid of january and had a horrible starting distribution, see drk, which is still in parts closed source due to bad distribution and the fear of clones.

see on the hand xcp, which is not cloned due to the consensus that the distribution is fair. see bytecoin which was cloned due to the distribution and which is now lacking success because of the market deciding that the clone is fairer.

if your coin does not have a bad distribution I see no reason why it should be cloned and therefore no reason why it shouldn't be open source.