Earlier quoted context omitted.
I'm an XP fan, but I'm always wary of saying "they didn't do real agile". It can descend into "No True Agile" pretty quickly, with a dash of victim-blaming. Agile is actually hard to get to grips with. It requires lots of discipline. So did the pre-agile methods that worked best. And it gets half-done for the same reason that the pre-agile methods got half-done. It's hard. Hard to do, hard to learn, tempting to stop.
Perhaps, but one problem often seen in large orgs (I've been there personally twice, and heard many more stories from close colleagues) is that they adopt the agile methodology (sprints, stories, etc), without adopting the culture shift (shit does not get added into the middle of a sprint, ever) necessary to make it work. Agile process without agile culture objectively isn't True Agile. It's worse than everything it…
Putting aside that particular nitpick, it's easy to cargo-cult the practices. I sometimes use the analogy of the introduction of lean manufacturing in the US. At first what was introduced were the tools: boards, line-stoppages etc. But tools are just tools, by themselves they're not enough.
The uncomfortable, expensive and difficult truth in our industry is that people, process and tooling are not substitutable. You need the best of all three that you can get.