Re: "Quality" is a structural attribute, not a bolt-on
Oh, Agile if done properly is fine, but it rarely is. The money men don't see the value of rigour regardless of whereabouts in a programme it crops up. Agile too readily gives them an excuse for dispensing with rigour altogether.
Also one of the tenets of Agile seems to be to embrace failure, let it happen, deal with it when it occurs. That might be fine for a Web IM service, where a day or so offline won't matter, but not elsewhere.