For them to struggle at something that (per your own comparison) you seem to think of as possible to do in a way so that it is worthy of praise (because you've compared them to ones who could do it in a praise-worthy way) shouldn't really be something that you have no sympathy towards, if you want everyone to do it the best way..? [Unless you mean that they are intentionally 'cheating', so to speak, and capable but self-centered]

Indeed, reason by analogy is not enough.

Edit: but there is a connection between farming and slavery, however feeble today. Keeping drugs illegal creates opportunity for quasi-slavery on far away large scale farms, I imagine.