"Agile in doctrine" is the kind all of the anti-Agile crowd rail against because they've been burnt by working for some company or manager who drank the Koolaid without actually understanding what Agile is. Blindly following some consultant's Agile playbook is not Agile.
"Agile in spirit" is a bit like The Zen of Python: X is usually better than Y but there are times where it makes complete sense to do Y. In order for Agile to work, you need to have leaders and CIs who understand that. Agile emphasizes communication and flexibility. Agile is advisory, not prescriptive.