The people who compared to the prior study are the authors of this study, right? Shouldn't you take up your complaint with them?

Or rather, don't, because the two studies clearly are comparable. The point of science, whether social or otherwise, is to tell us true things about the world. If the response to comparing the results of two very similar studies is "you can't do that" then this research effort isn't producing generalizable knowledge, which makes it worthless.