"Good without God"

Jerry Coyne writes, in this op-ed, that "[a]s atheists know, you can be good without God."  What the piece is actually about, though, is not the not-very-interesting question, "Can an atheist be 'good'?" (Of course he or she can), but rather, "does morality come from God?"  Coyne says:

But though both moral and immoral behaviors can be promoted by religions, morality itself — either in individual behavior or social codes — simply cannot come from the will or commands of a God. This has been recognized by philosophers since the time of Plato. . . .

Then, after citing examples from the Bible and other religious texts in which God appears to command or will bad things, Coyne writes:

When religious people pick and choose their morality from Scripture, they clearly do so based on extrareligious notions of what's moral. . ..

And then:

Secular morality is what pushes religion to improve its own dogma on issues such as slavery and the treatment of women. . .

And so on.  The question that is not, it seems to me, really acknowledged or engaged is whether, if there were no God, "secular morality" would be true.  As a number of learned people (Perry, Wolterstorff, etc.) have suggested, it is not at all obvious that, for example, the claims proposed in human-rights discourse have any foundation (though they certain sound nice and yield good results) if it is not the case that we are made and loved by God.