It may be that the brake lines stretched a bit after a few rides and on the ride where the brakes failed to slow my wife down was when they were just stretched a bit too much.
It should not stretch more than a mm or so,that would not prevent you from slowing down or stopping,unless one pad flew off.Both brakes?
That attitude explains why garbage dumps are overflowing. It is exactly the mentality that people need to get away from, not propagate.
They are overflowing with wal-mart bikes because not everyone can afford a trek or giant,in lazy obese america who rides a bike anyway?