I think Agile get's a bad reputation because maybe 5 teams ever have actually implemented it the way it was intended. So all of us have experience with a bunch of half-assed approaches, patches, and workarounds.
Granted, this is mostly still a problem with Agile. Agile's core problem is it's pretty much incompatible with strict corporate hierarchies, which is what most people work in. You'll get the blessing of your PM, or manager, or whoever, but they typically don't understand that adopting Agile fundamentally means cutting them out and giving that power to the team and customer.
This works until basically the team and customer disagree with the manager, and then it all gets thrown out the window, but they still keep calling themselves Agile.