If Lisp wasn't compelling enough because of the perceived lack of libraries, then Arc is the last way to come back to Lisp as it has NIL.
I think you've misunderstood this sentence, which explains why you don't understand the logic.
He is dismissing Lisp because [library pain] is not alleviated by [compelling language features]. For him, in Arc, [compelling language features] do alleviate [library pain], so he is happy to use Arc. This logic is fine even if the [library pain] in Arc is actually worse than the [library pain] he experienced in Lisp, because [compelling language features] differs too.
So, no hypocrisy. You could still argue that he should have experienced less library pain in Lisp than he did experience, or that Lisp might have compelling features that he overlooked, or even that library pain cannot in principle be alleviated by language features, though I won't comment there.
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If Lisp wasn't compelling enough because of the perceived lack of libraries, then Arc is the last way to come back to Lisp as it has NIL.
I think you've misunderstood this sentence, which explains why you don't understand the logic.
He is dismissing Lisp because [library pain] is not alleviated by [compelling language features]. For him, in Arc, [compelling language features] do alleviate [library pain], so he is happy to use Arc. This logic is fine even if the [library pain] in Arc is actually worse than the [library pain] he experienced in Lisp, because [compelling language features] differs too.
So, no hypocrisy. You could still argue that he should have experienced less library pain in Lisp than he did experience, or that Lisp might have compelling features that he overlooked, or even that library pain cannot in principle be alleviated by language features, though I won't comment there.