This is not the first time I have read something like this
"Helen Wyman climbs one of several steep ascents to the top of the bowl-shaped valley in which the race unfolded. “I had a bit of braking issue today,” she said. “This is the first year I’ve ever used disc brakes, and this was the first proper ’cross race. They were amazing, and then after two laps they just failed completely and I was without brakes.”"
Nationals last year was another good example. What I find interesting is that when they work, disc's are great. And they let you run carbon rims is the crap. But in all of the years I rode canti's or v-brakes, I NEVER heard anything like this.
Personally, I have disc's on my sole remaining cross bike but I too have had them just fail. They actually take more maintenance than my old brakes did. Funny how I don't have this problem on my mountain bike :) Perhaps Hydro's will solve many of these issues ... who knows.
I do know that if I was building a light cross bike from scratch today I would probably not run disc's. If I was building an all around gravel/cross bike I probably would ... with a grain of salt.