[weinzierl]

I have no idea, but a wild guess is that with old hardware the "hot" pixel that could trigger the collision interrupt was fixed to the upper left corner of the hardware sprite.

EDIT: Another thought that crossed my mind is that with very lo-res screens a corner is the only way to get a well defined and sharp (yet fairly wide) arrowhead. The trade-off would be the shaft being pixelated, but the tip is more important.

[jusuhi]

If you'd actually read wherever the link is going then you could get an idea instead of just speculating wildly.

[rgj]

That was debunked 10 years ago https://news.ycombinator.com/item?id=7253841

[p-e-w]

Did early workstations support hardware cursors?