Interesting discussion. As freelance developer I have years of experience using corporate CMS's based on SAP, and would never imagine a scenario without different environments.
Minimum is always 3. Dev, Test and Prod. But I've been with customers where 4 or more is the norm.
The lack of any sort of support on this area when using Wordpress (or any othe open source CMS for that matter) is something that really frightens me. Not only from a maintenance perspective, but also when you're trying new stuff, were you're often forced to try that in Production.

That is why I find the idea of Flat File CMS's (like Kirby http://getkirby.com/ for example) a very interesting alternative (at least when it comes to solve this developers dilemma).

I'm not comparing which type of CMS is better, or want to dive into the DB or no DB debate.

But the fact that replicating an environment (content included) happens in a snap, makes me consider very seriously the Flat File CMS option.

Any thoughts on this ?

Cheers.