I've seen a massive amount of indictment of the ignorant online. Of course, it seems perfectly justified especially how confidently incorrect information is spouted (both on and offline). And especially now, when we live in the "information age" (so 90s).
However, broadly, almost all people hold beliefs that are incorrect, or at least a very loose approximation of what is correct. A lot of those beliefs are ones that don't actually affect that person individually. For instance, a carpenter probably has incorrect beliefs about (say) how his GPS knows where it is, but it only matters that it does, not why. This is only a problem if he's explaining why he thinks that lizard people that control the GPS secretly control us, but for the most part it will be a benign belief system.
And that's fine.
Knowing about things takes effort and time. Admittedly less effort and time than ever before in history, but nonetheless at least some. And the more complex and nuanced the subject, the more effort and time it takes to gain enough of an understanding of a subject that the majority of trained people would agree with.
Online, I see the opposing view phrased with "there's no excuse not to know a little bit of <insert topic of choice here>". Far be it from me to recommend that one argues based on unsubstantiated knowledge, but having a benign ignorance is not a moral weakness.
It would take a ridiculous amount of time to learn all the information an individual with internet access has access to. Probably more than the amount of time in a day. Even to get to a well trained level in every topic would require far more time in a day than people are willing to put in after feeding their children and working their 9-5. We all do it (well, I do, and you might, and if you don't, then congratulation. Just one).
Thus, it is important to accept that almost everyone doesn't know as much as you do about your pet fields of study. My carpenter friend does not know how his GPS knows where he is without the satellites knowing, and I don't know when to use different kinds of, uh, carpentry tool. Thus, it's also important to accept that you don't know as much about their pet topics as they do (unless they are supremely boring people, or very young, or both*). And from that, you shouldn't attack people for not knowing about your pet topic.
I think politicians get the worst rap for this, but it is actually partly justified. Again, accept that a politician has no time to learn all about the topics he is legislating on. However, what he and his political peers legislate has a massive effect on how those relevant industries develop. Thus, their writing should be scrutinised by reasonably partial members of the industry and picked apart like nothing else. Obviously, carpenters shouldn't be able to say "carpenters must now be paid a significant portion of their country's GDP for a job", but carpenters should have an avenue to "read in" potential carpentry legislation.
Now, this looks like lobbying, and it is, at a base level. However, the way it currently works is that industries tend to send highly paid (and relatively speaking, highly vocal) lobbyists to politicians. And those industries should have that voice. But that voice should not be significantly more than the educated users, non-sponsored members of the industry, or other considerations (e.g. miners are harmed, for instance, by environmental considerations, at least in the short term).
But outside of politics, it probably doesn't matter if someone says "The Great Wall of China can be seen from the moon" or whatever, unless they are trying to use that "fact" to support an argument. Just chill.