It’s funny, it seems to be where the cable curves around the ’round bit’ on the disc brake which moves when the cable is pulled via the brake lever, I saw the cable on a stranger’s bike fraying around that curve a few years ago, and went and told the reception staff of the place it was locked up incase they had an accident on thier way home, and i’ve just read about somebody having to keep an eye on thier cables due the cables fraying at the same point.
It’s not a sharp turn, but it seems like enough to cause the cables to fray over time, going just on anecdotal evidence.
I’ve noticed no Avid BB brakes have a similar curve in the cable at the brake end, which seems like it could be interesting when people havn’t had cables fraying over a number of years of using them.