Since when has science been reasonable? :)
In situations like this, I tend to speak in theoretical absolutes. A computer that "could - like humans - learn to produce infinite, novel, contextual, and meaningful grammatical utterances" isn't even on the timeline right now, but it's the theoretical goal in showing that we understand language acquisition (ontogenetic development), evolution (phylogenetic development), and production.
Just because that goals seems unattainable doesn't, to me, mean that we need to aim any lower. Now, this is premised on my belief that mimicking phenomena with statistical learning is not as intellectually satisfying as understanding the underlying cognitive systems, but that's not believed by everyone.