Agile is good for refining, not defining.

If you have an existing product that you want to develop to the next level, then Agile in its truest sense works because you have a base upon which to improve. This means that if you know what your requirements are and these have been properly informed with user research, comparative analysis, business objectives, and analysis of what content you have and what you can technically achieve, then Agile alone can work well.

 

But spending money on software development without a plan of what to build is like asking a construction crew to erect a tower with no blueprint. Some level of plan is necessary to avoid a Frankenstein of each individual’s perspective on the best design solution.

This is a well written article with some criticisms of Agile processes (SCRUM) that are perfectly valid. I've experienced some of the same pain at my new job.

It doesn't invalidate Agile, but it does re-evaluate when in the entire process of software development that Agile(ness) is valid.