Was he really arguing that the art lacks value, though?...the original review seems to be more making the (obvious) point that the social media channel and performative use thereof is a core element of his work.

I think he is. The original review and follow-up are not making the point that the social media element is a core element of his work, but rather the core element.

Davis' says things like the work is not presented in an "actual gallery." Describes his work as "conventional" and a hand in one of the works as looking "like a small rotisserie chicken." Beyond saying that Rodriguez is a good a technical painter, Davis doesn't really say anything much positive that would imply he thinks the works have value.

Really, both articles pretty clearly state that the paintings don't have enough value to stand on their own merit, and are instead only popular due to the way Rodriquez has marketed them. Which Davis' then presents that as problematic due to the fact that the situations are faked.

So if he thinks the work is lacklustre, and then also find Davis' social media problematic, then he's essentially calling the whole thing shite. Then he acts surprised about backlash from his fans...