I'd say it's that people tend to use Agile because consultants tell them they can be piss poor managers dealing with the crappiest developers and stupid business ideas and still make awesome stuff if they just make everything buzzword compatible.

I'd say projects without much of an upfront project plan can still be very successful, but it's all about having a quality team, which isn't something a two week 'training and consultancy' session isn't going to get you, so there's no big marketing behind that sort of message.