No it doesn't. The conclusion supported is far too close to the 'middle ground' on the issue to readily pattern match to rationalization and seems to be a description of considered reasoning from plausibly held premises. The 'rationalisation' and 'pre-determined belief' charges could be credibly made in response to many of the comments in this thread but doesn't apply to the grandparent.

Respectfully disagree, though we may be focusing on different parts. It worries me that your analysis seems to focus on the conclusion drawn rather than the procedures followed.

Consider this bit of the great-grandparent:

2) Reasoning that Takes Relevant Data Into Account: "The IQ test(s) said African's IQs are lower than those of whites. However, there are known flaws with IQ tests such as cultural bias, so that figure might be wrong. Most published research findings are false (PLOS Medicine), so I should apply healthy skepticism to all the research I read. This is not likely to be an accurate piece of data to use as a Bayesian prior. Once I've decided on a prior to use, I should then adjust for other relevant data (things I know about the specific individual).

This looks like pure rationalization to me, with many inaccuracies and irrelevancies, all of which support the intended conclusion. (An unbiased sloppy thinker should be expected to make mistakes in both directions simultaneously; when the mistakes all point one way it suggests bias.) The most egregious irrelevance is the attempt to discredit one of the most replicated findings in social science with a study that showed that prominently promoted recent research often fails to replicate. The last sentence is bizarre by its addition- would someone using race as Bayesian evidence not update on other information? (The later reference on Bayesian updating is similarly bizarre.)

The rest of the great-grandparent discusses how, even if we had an estimate, we should be careful how we use that estimate. Of course--who would argue against using estimates carefully?--but irrelevant to the question of whether or not it is ethical to use Bayesian reasoning.