[memracom]

Júlio Turolla Ribeiro's answer is far better. I guess that young people have lost the ability to think outside the computer. Some of us still remember school classes, and business presentations in which presenters pointed at the board with their finger, or with a two meter long stick called a "pointer". The pointing was almost always in the same angle as the photo that Julio included, either from the left or the right. Of course, from the right is more natural for the right-handed majority.

The fact that some engineer tinkered with the computer representation of the pointer for code efficiency reasons, does not change the fact of hundreds of years of history in which teachers pointed at an angle from the right. I'm sure that if you hunt up old movies (black and white ones) where there is a school/university lesson being portrayed, you will see a pointer in use in this pose.

[gertef]

1. On my computer, the pointer arrow is asymmetric, and the left side of the arrow-head is vertical.

2. Forget pre-computers... If you draw an imaginary line from my mouse/hand to the cursor, it is approximately parallel/overlapping with the line of the arrow pointing.