In the meantime, I think these are generally the same shallow straw-man arguments against Scrum that we all see pretty frequently. I guess the key points to bear in mind will be:
- Scrum is not a be-all and end-all solution to all product development. If you are developing a product for a slow-moving third-party (a case which is described as one of Scrum's downfalls) then you are correct – it's probably a bad choice. So is any agile approach. That is totally fine, and I'm not sure why it's seen as a bad thing.
- Scrum is not a fully-described, cast-iron set of rules that have to be followed. It's a framework which can (and must!) be changed to suit the team, and the product that's being developed. Concerns like wider-scale management and integration of multiple projects are so dependent on the functioning of an individual organisation that it would be ineffective to have a prescriptive set of rules. Your 'Agile Coach', product owners and management team generally have to deal with these issues in other ways.
- Scrum is (apparently, based on the objections in this article) implemented poorly in many places. For example, the 'seemingly endless series of meetings'? That's explicitly one of the things that Scrum does not encourage! Micromanagement is the same. Scope change during a sprint as well. That Scrum is poorly implemented is not a reasonable criticism of it, for me.
- It's okay to fail to meet targets when delivering software, and inevitable that it will happen. Scrum provides the tools to manage and recover from those failures, and to help ensure they are limited in scope. Those retrospectives, for example – it's totally valid to say 'We committed to feature <x>, and failed to deliver it because <unforeseen dependency y> prevented us from doing so'. The important thing is to understand what caused that failure, and how similar failures can be prevented in the future. That's a fantastically powerful tool to have.
Perhaps I'm just biased, because I've been working in excellently-managed agile teams that have been delivering software very effectively, and have seen how useful Scrum has been as a framework to manage the complexity of planning it.