In the couple of times I have looked at lengthy comments sections in those papers I've been astounded that lurking beneath the article there lies a morass of the rude, the confused, the spiteful, the hateful and the downright idiotic. Humans tend not to comment so much if they agree - much more so if they disagree, which is why you are going to find so much hasty bile from the commenters - particularity as so many people are prone to crass misunderstandings and impulsive distortions.
Even in papers like The Guardian - a place where article writers continually get lots wrong - the average article writer is likely to be significantly brighter than most of the people commenting, which adds further weight to the probability that you don't need to read any further than the article itself
On the other hand, there are blogs (The Adam Smith Institute blog, and the blogs of David Friedman and Tyler Cowen, to name but three) that do have huge a readership (though not the size of the Guardian or Telegraph) and also bright and engaging commenters (ASI aside, I still don't read the comments very often, but not for the reasons I don't read comments generally).
This higher standard is probably a combination of a) having a moderator who ensures only respectful comments are published, and b) having fewer, more intellectually bright, curious and discerning readers than your average Guardian or Telegraph article.
This led me to ponder what sort of readers my own blog has. The calibre of my Philosophical Muser Blog readers is going to be, on average, quite high I'd suggest. But what about the calibre of my commenters? Well, given that most people only tend to comment when they disagree, and given that (quite naturally, being the writer) if they disagree I'm going to think they are wrong (and be very willing to engage in debate to try to show it), the corollary ought to be that the average calibre of someone who comments negatively is going to be significantly lower than the average calibre of readers overall, and the argument they've presented is not only likely to be sub-standard, it is likely to be poorly constructed.
And if I'm right about that, I can think of a good way you can to put it to the test. Go onto Amazon and pick a non-fiction book you think is excellent, and has been acclaimed as excellent by the cognoscenti. Then look at the book reviews - just the five star and the one star will do. What you'll probably find is that in most cases the five star reviews will look as though they are well-written and intelligent, whereas the one star reviews will look as though are poorly-written by overly-emotive simpletons. Further, I'd expect the five star reviews to have a good grasp of the material, and the one star reviews to have a far less clear understanding of the material.
So, then, to all my readers out there (thanks for reading, by the way), if you are someone who likes this blog, finds it intelligent, engages with the material consistent with the author's intention, and pretty much agrees with everything, then the majority of internet data out there indicates that you are a smart, intelligent individual.
If, however, you are someone who is always disagreeing with this blog, and frequently itching to give the articles you read a negative review, then the majority of internet data out there indicates there's a high chance that you have a lot of work ahead of you. LOL!