I have heard the arguments for it, and it is just not convincing.
Now, I could see some kind of quirk of personality or perspective shift, but the fact that reality isn't what you thought isn't gonna break your mind.
When I learned how relativity worked, I was pretty tripped out, but after a little while I was just like: "OK, now I know how things will work if I approach the speed of light, and how objects which approach those speeds are affected."
It didn't break my mind, or anything even close.
The whole "Things man was not meant to know" seems pretty silly to me.
And horrible things like child molestation don't make me go insane.
They make me want to see that person executed.
They make me angry, not insane.
The idea of reality mocking a pseudo-reality doesn't creep me out, it just seems absurd.
Mockery demonstrates intent, and reality is not "alive", it does not have conciousness.
What if it was alive?
Well, that would be trippy, like Relativity, but then it would just be "Accept it and move on."
The mind functions in such a way to be adaptive.
Well, whats insanity then, right?
Frequently it is an organic disorder, that is, essentially genetically encoded brain damage.
Lets say I get a baseball bat and crack you on the head with it.
I can cause "insanity".
Not exactly terrifying.
And personality disorders are rarely terrifying, they are usually just sad.
I don't know, I mean have read CoC stuff, and it is pretty creepy at times (which is pretty cool), but to me it all boils down to get a gun and blow its head off.
If that doesn't work, then either I need a more effective "gun" (or spell, or whatever),or the whole thing is just stupid.
Some kind of "temporary psyche-shock" would work, I think, in extreme cases, but thats about it.
Everything can be deconstructed to the systems of reality, whatever that reality is.
Which is just not scary.
Cthulhu is just an alternate system of reality.