Are they? Really? We know that NSA has lots of vectors for exploiting the system AROUND encryption. We have pretty solid evidence that the NSA has weakened some encryption standards to make them crackable.
We DON'T have evidence that encryption developed outside the milieu of the NSA are equally crackable. And circumstantial evidence suggests quite the opposite.
The problem is that there are lots of things to get right to get crypto right, and getting even one wrong leads to failure. Which is why we tell people not to roll their own encyption and to let the experts do it.
Another problem with too many people rolling their own encryption is that it dilutes attention and no system gets sufficiently audited.