Not true; that's a framing mistake. It's really similar to Gilbert Ryle's idea of category mistakes.
"Sense" and "senseless" are both related, in general, to the issue of agency. And obviously, nature (unless one is a New Ager) isn't a personal being with powers of agency. A good existentialist could do more to straighten out Keller.
That's just the first of four straw men that Keller sets up to knock down.
The second is that this means that any god who exists is less than omnipotent.
But that kind of God doesn’t really fit our definition of “God.” So that thinking hardly helps us with reconciling God and suffering.Well, maybe your definition is wrong. Isn't it arrogant to assume it isn't? And, that's a problem I have with theologically liberal Christians. It's for similar reasons I unfriended on Facebook, and eventually blocked there, a Harvard Divinity student who claimed Plato's famous Euthyphro dilemma (is "good" what it is because god orders it? then god can be capricious; is "good" what it is by its own nature? then "good" has moral standing independent of god) didn't apply to the god of Christianity.
(Honest grasping of the dilemma, perhaps through distinguishing between contingent and necessary moral truths, while ultimately a failure, would still be an effort, at least, not a craven dismissal. The "false dilemma" claims of some Christian Fathers, as listed on Wikipedia, aren't very good, either; they're halfway on the road to the ontological argument for god's existence, and it's no wonder Anselm is among those making this claim.)
The third one is that some people suffer because they're more evil. Well, about no nontheist claims that. Many of us do claim that, within a monotheistic theodicy, it sure looks that way, though, even if we're not Gnu Atheist knife-twisters.
Fourth is what he says is a half-answer; it's the will of god, we have to but accept.
He spins on this to go to us needing to be like children before god.
Not true. In fact, a god who creates sentient, curious, thinking beings, but then says "hey, wait a minute" and hides behind inscrutability is ultimately guilty of inflicting psychological evil on those creatures, thereby making the "problem of evil" worse, if anything.
Now Keller is just a parish pastor, not a theologian. Nonetheless, he's a pastor in New York City for a mainline, vaguely liberal Protestant denomination. And, he can't do better than this?