Because they look poor quality (unrefined machining, no crown, lack of radiused edges, etc), and the timing device looks subpar.
Besides price (I'm assuming these are cheap based on the lack of features and quality), what does this brake do better then an Insite Arms Heathen, PVA Jetblast, APA bastard, Area419 Sidewinder, etc? Why should I pick it over these brakes?