No designated desks is the Agile of floor planning. Everyone's the same, anyone can do the same job, you can hotswap spaces and people as you replace hard drives.
While I agree with your overall point, I would add that anybody who thinks that "Agile" prescribes that people be considered fungible, has been misled. Somebody's specific implementation of "agile" might prescribe that, but nothing in the Agile Manifesto says anything like that.
In fact, I'd argue that, to a first approximation, anytime anybody makes a statement along the lines of "Agile says you do X", you can safely assume that they don't know WTF they are talking about, and/or they are confusing Agile with "Foobar Inc. Fucked-up Agile".
