Leibniz and Arminius

Again, finally, if I cannot accept that this is the best of all possible worlds, and with it the belief that even the Holocaust was “for the best,” then I cannot logically accept that God plans, ordains and governs everything in the sense that Calvin clearly meant it as did Edwards and as do most spokesmen for “the new Calvinism” today. 

http://www.patheos.com/blogs/rogereolson/2014/06/is-this-the-best-of-all-possible-worlds-what-i-would-think-if-i-were-a-calvinist/

Olson seems to be making a general point, and not just an objection to Calvinism in particular. He seems to be saying that a world containing the Holocaust can't be the best possible world. 

Now, although his post is targeting Calvinism, his principle raises corresponding questions about Arminianism. From an Arminian standpoint, does he believe this world is the best possible world? He seems to think the existence of the Holocaust renders that contention absurd. 

But if there are better possible worlds, then why didn't the Arminian God make one of the better possible worlds, instead of our world, which is worse, or maybe even one of the worst? 

Will he say that God was constrained by human freewill? Even if he thinks human freedom limits the kind of world God can make, then isn't he committed to the proposition that this is the best world God could make? Of the available worlds, ranging from best to worst, there was no better world God could make given the constraints imposed on God's field of action by human freewill. 

At the very least, then, Olson has to say a world containing the Holocaust is the best practically possible world. 

By best possible world, does he mean what's logically possible or actually possible? Keep in mind that as a critic of Molinism, Olson can't avail himself of the possible/feasible distinction.