Agile is a very specific process. It’s got very specific requirements, roles and processes. You can get certified in agile. I once worked at a company that followed agile very closely and made everyone get certified. There is some flexibility in Agile, like sprint lengths and some of the business roles, but the purpose of Agile is to follow it’s strict methods.
I’m not saying I support follow strict Agile methodology, it depends on the company and company lifestyle. The company I worked it pulled off pretty well and managed to be consistent on enforcing agile rules (especially when it came to scrum lengths and producing unit tests). I remember one time a team lead was admonished for having scrum that was longer than 15 minutes. The thing is, when it works, and is done exactly, it works really, really well. We were like a well-oiled machine. It feels really good when, as a developer, you know what to expect from release to release and everything was very concrete. But pay wasn’t very good, and the company was kind of an H1B visa factory, so I eventually left. I miss that place sometimes.
But most companies don’t follow Agile strictly, or part of the company does, and part of it doesn’t, and I think that’s why there is a lot of heartburn over it. Instead, people choose instead to follow its methodology very loosely. You need a company’s full commitment to follow through for it to work.