I fully accept that they are a paperclip with a thing on the end. You are missing the point though.. it's easy to say that one could make one but the following reasons make it the lesser option.
1/ the paper clip is bent at 6mm, any further you minimise grip. one can't bend by hand at 6mm
2/ self bending severely mis-shapes the clip.
3/ putting a head on the clip (bent forward), easy to grasp, easy to see and being forward raises the page so you can get fingers underneath if you need to return
4/self made would only be a makeshift example and it is highly unlikely that one would
5/ It is a saleable product, that any teacher can sell to students.
But hey ho, everyones entitled to their opinion, but for me "IT WORKS"
REGARDS;
MARTIN