It's very true that we only approximate truth with our maps. All abstractions are leaky, but that fact does not imply "catastrophic relativism" (as the grandfather post phrased it). It just implies that we need better, more accurate, maps.

Or, to return the topic of the post, it just means that our translations need to try a little harder, not that human quality translation is impossible to do via machine.

I think it's very important to remember that objective truth exists, because some large percentage of society has a political interest in denying that, and we're slipping ever closer into Sagan's "Demon Haunted World."