You can also read why those people are misguided.
But instead of doing the irrelevant art analogies again, go back to the article and cite a specific principle that is violated by blur.
It has a list:
> Now, what does it mean in practice?
Also, blur doesn't even look weird statically! And again, provide at least one example where it looks weird to our eyes
> This is the case of file picker example.
You also don't seem to understand what that example shows, the "blur/crisp" is not at issue here, it's, for example, "textedit" jumping on top of "where".
Now explain what non-artistic human vision benefit there is to 2 words being drawn on top of one another in a UI transition instead of the first word disappearing completely before the second moves to its place.