I guess to some this will perfectly okay "cos it's our guys doin' it!"
Part of the NSA's mission is to protect government systems from cyber-terrorism. So, they have a legitimate reason for wanting to
improve security - not just break it.
Second, the problem with back doors is that
other people inevitably find & use them - both other governments and cyber criminals. This is the strongest argument against backdoors, really. So, they're bad no matter matter who is adding them. And it would be especially dumb to try and add them in an open source codebase that everyone (security researchers and hackers, alike) can analyze.
I'm somewhat disappointed in Lucian. His articles are usually better than this.