Because there's some idiot out there who thinks gold plated connectors matter on an optical cable and Monster Cable doesn't let ethics stand in the way of making a quick buck or two (or in their case, a quick hundred bucks)
monoprice.com FTW!
Didn't they do some sort of an A/B test using Monster Cables vs. modified coat hangers, and hardly anyone (if anyone) was able to tell the difference?
I have one Monster Cable and it was a gift. I'll keep it just because if it breaks all I do is take it to Guitar Center and get a new one for free. Other than that, monoprice is the only way to go!