Please stop using a very common name as a derogative! It's insulting to the women who have that name. Also, as you noticed, there is no male version of it. It's a decidedly sexist meme that shouldn't be promoted.
Joe Public of course is usually well aware of this usage and doesn't actually think all people with these names are the sterotype they represent.
It is, and most of these memes keep some of the levity of their comedian origins. This particular meme seems unusually nasty and serious in comparison, but maybe it's just because it hurts someone close to me.
I suppose that doesn't change the fact it's a bit crappy for all the perfectly decent people called Karen out there. While I think this behaviour does need a good snarl word to call it out when it happens, perhaps "Karen" isn't it and we can do better.