In case you're taking this seriously, consider other possible explanations. Maybe more eloquent people are less likely to write negative reviews in general, not

In case you're taking this seriously, consider other possible explanations. Maybe more eloquent people are less likely to write negative reviews in general, not just for this book. Maybe feeling negative makes a person less eloquent. Maybe this book was marketed to a group of people who are generally educated but gullible when it comes to the subject matter. It could be that their critics are idiots, but this isn't much evidence. (And I'm pretty sure they're joking.)