Agreed. As a rule of thumb, if you're arguing with someone about something they've spent more time learning/thinking about, you're probably wrong. While it's often said that reality has a well-known liberal bias, I find that this rule tends to apply equally across the aisle.
This is also the problem with the Skeptic movement, in that it's fundamentally about discouraging people from reading books.
(And note that I'm not saying the other person is probably right, only that you're probably wrong.)
Take a look at any of the popular skeptic publications, e.g. skepdic.com or sciencebasedmedicine.org, or at many of the numerous 'takedowns' of popular books that get posted on sites like HN or BoingBoing. The thing that most of these articles have in common is that they're generally designed to discourage people from reading the actual original sources. The whole value proposition is basically "you don't have to read this book about X, because we'll read it for you and tell you why it's wrong."
The problem is that skeptics themselves are wrong as often as not. And worse, the people reading these blog posts and articles never figure it out because they've bought into the idea that the original sources aren't worth reading. And the skeptics know this, so often they wildly distort the arguments of the original authors since they know they can rack up millions of pageviews from people who will never be the wiser.
Worse still, these people claim to be well-educated, when in reality they're basically destroying the Internet and undermining democracy. One site that I think gets it right is Amazon, because when people leave 1-star (or 5-star) reviews of a book without having actually read it or are wildly misrepresenting the ideas within, it's at least significantly easier (if not always easy) to tell this because of the surrounding context. But in general, while the ideas that skeptics profess to believe may be laudable, ultimately the whole worldview is like a game of telephone; even if the original analysis of any given subject was correct, once it's filtered through a dozen people who don't read books listening to other people who don't read books, all that's left is hollow dogma.
I must admit I'm not hugely familiar with the sites you list, but claiming that negative book reviews are "basically destroying the Internet and undermining democracy" is one of the most extraordinary claims I've seen on here.
The raison d'être for democracy, and to an extent the internet, is the assumption that self-appointed experts' views can and should be challenged, and a challenge in the form of a several hundred word takedown of the author's alleged misuse of statistics in chapter five hardly constitutes metaphorical book burning. People that give up on buying a book (or believing anything it says) after reading the first snarky article probably aren't the audience the author was after anyway... unless the original author was specifically targeting the easily swayed. In which case it's the skeptic blogger who's the one most likely writing in good faith, complete with a public comment plugin and an affiliate link to further aid those who want to make up their own mind.
N.B I'm reading Graeber's much criticised "Debt: The First 5,000 Years" right now partly because it seems to provoke internet judges into pulling apart his fact-checking (and yeah, they're right on all counts... it's ambitious enough in scope to be interesting even to those who can't stand Graeber's politics, and yet trivially easy to pull apart if you're remotely familiar with parts of the subject matter even if you think he's making good points). The layman is much better off reading it whilst considering the possibility Graeber's anecdotes and understanding might have been stretched to his limits at points.
What I'm criticizing isn't negative book reviews per se; rather, negative book reviews are just one tangible expression of Skepticism as an ideology.
I'll be the first to admit that negative book reviews are highly useful, and most don't even fall within the realm of the Skeptic community. E.g. economics isn't an issue that the skeptic community has much interest in. (Which really says something about the skeptic community in and of itself.)
The issue is when you get scientists who spend years researching some issue, and then bunch of jackasses come along and publish a bunch of articles criticizing their methodology without having read the paper or having any idea what the methodology even was. That sort of behavior is endemic in the Skeptic community, and whether it's rational or not it absolutely does discourage people from actually learning stuff that might better themselves or society. I'd give specific examples, but it's so ubiquitous it's not even worth it; most people just don't notice because again, they haven't read the actual stuff that's being criticized.
This is also the problem with the Skeptic movement, in that it's fundamentally about discouraging people from reading books.
(And note that I'm not saying the other person is probably right, only that you're probably wrong.)