I will say you have some problem relatives. But then, so do we all.
There are, I think, two kinds of stupidity. We are born stupid as in lacking both information and experience and we are made stupid by someone reinforcing a ridiculous position or statement to which we fail to apply logic.
Wilful stupidity, as you have in the title here, results from willful ignorance. In fact I’ve long called that the only unforgivable sin. The ironic source of the concept of an unforgivable sin is, of course, christianity, which demands willful ignorance of people and then tries to lie that something else is worse.
We need to pause here for me to say that I think that I am now haunted by your two examples. Both cases are so clearly and supremely stupid that I would be concerned at being in the same county with those people.
Please tell me that you made them up.
The real problem is those people who have decided it is not only ok to be wilfully ignorant and therefore stupid but that it is a right. This has been refined to the point that it is the sole topic of Donald Trump and his remaining followers. Trump’s rallies (is that what they are called?) are a few hundred people who appear out of nowhere and then shout stupid things at each other.
I originally assumed this was so that they could learn new stupid things to shout but that indicated my stupidity because why find new stupid things to shout when you have old stupid things that you already know. This is illustrated by them shouting ‘lock her up’ for reasons that escape me and have long since escaped them.
Unfortunately I don’t have a solution to this problem. I hope it is not catching so that they will eventually die out. I’m a little worried about that, though.