Maybe he's saying the Roman would be looking for information to use for better farming or the like, but if there is one thing the poem is devoid of it's "practical" application like mechanics or hydraulics.
I think that's what he's saying, that Lucretius is pushing atomism even though it doesn't seem practical to the typical Roman of his time. But he seems to be missing or ignoring how the understanding of atomism can free people from religious oppression. I read into this the idea of a spoonful of honey to help the wormwood go down but I don't see him saying this.
Interesting find!