This is the point… The meme works on 2 levels.
Lay people will assume because the angle isn’t 90, that it will annoy perfectionists. But this is false.
It does still annoy perfectionists, but for the reasons you describe, not the reasons lay people assume.
This makes the meme funnier.
Buy/collect used books off students after they finish the course… Remove the ink, resell undercutting him by a ton and make a huge profit!