I believe it was because it was such a weird and dramatic shift in tone from the regular CAD content, which was not all that great to begin with. You probably had to be there (I wasn't).
Xkcd did something similar but afaik nobody made a big deal about it, only that Randall kept the depressed tone for quite a long time, after which people started to complain
Honestly, I am probably exactly the right age for this and I just learned what it was a couple months ago. Because the format is so bland it just blends in with the doom scrolling, I never bothered to find out what it came from and most certainly never even noticed any of its derivatives were trying to be the loss meme instead of making some mediocre point or art.
Depends how old you are, this is quite an old meme so it's possible you're too young to be very familiar with its origin, but I just don't know your age