Maybe; most people on this Forum don't seem to have very much of a good word to say for lexicographers.
I haven't seen anyone criticising them. They're dutiful if rather focused scholars and they do a useful job. It's just not the job you think they do. They document and categorize, instead of making pronouncements.
OK, I'm happy to dispense with the word 'define'; I don't think it's paticularly important. The key points are the word 'meaning' (which some posters have disputed), and, therefore, the fact that the main use of a dictionary is for consultation in order to understand what words mean.
Actually, I think you'll find that the main use of a dictionary is to check the spelling of a word that people know but are unsure of the "commonly accepted" spelling. For example, I'm rather embarassed that I don't know how to spell "embarrassed." Is there one r or two? How many s's are there? Fortunately, I have a dictionary to hand that will tell me if I need to find out. That's a commendable -- commendible? comendeble? -- trait of a dictionary.
I'm not sure whether this alteration corrects the so-called wrong, but even if your explanation of the historical purpose of a dictionary is correct, surely it doesn't apply now.
You think that there aren't regional dialects today?
Hint: what's the large piece of furniture, the one that seats three or more people, called? You know, the big thing in the room where you watch TV? For that matter, what's the room where you watch TV called? And the sweet carbonated beverage you drink while watching it?
Why else do most households have one?
Spelling corrections, mostly. The other main reason, of course, is that many of the words are not "common" in the sense that absolutely everyone knows them -- those words are almost never looked up. The words that are looked for some people to be unfamiliar with them, despite being relatively common in other contexts. "Massive" is a poor example, because almost every speaker knows what it means (and so no one's likely to look it up). But do you know what a "trope" is? (I didn't until about a year ago, when I encountered it in a scholarly paper from outside my field. It's quite common in some types of lit-crit, though.)
The best way to think about a dictionary is in comparison to other reference works. Think, for example, about a phone book. It's very useful, because it's close to accurate. If I don't know someone's phone number, the phone book is a good spot to start. Now,
some people have ex-directory numbers, some other people have changed numbers recently, and there are simply some typos. But if the phone book says my number is 381-1852, but my phone rings when someone dials 318-1852, is the phone book wrong, or is my phone?
Similarly, road atlases are very useful for finding your way around. But the cartographers model the streets, not the other way around. If it turns out that there is a road on the map that was ripped out five years ago, is the cartographer or the road engineer the one who made a mistake?
Heck, think of birding books.
Birds of the American Southwest. Very useful if you want to know what a roadrunner
really looks like. But if there happens to be a penguin by the side of the road (perhaps an escaped pet, or perhaps an undocumented subspecies of penguin that biologists don't know about), are you going to go by the book and say that the penguin doesn't exist, or are you going to go by the actual physical bird? Because nature doesn't go put penguins where the book tells her to. The book describes where (as best we can tell) nature put the penguins.