[jbroman]

Sure, but a credentialed person is more likely to be familiar with other research in the area and have expertise with state of the art techniques in the field.

So an uninformed reader (with less background than either to critically evaluate the work) should, all else equal, prefer the analysis of an expert. That's not to say the expert cannot be wrong, but a non-expert has a greater need to establish the credibility of their argument.