I like using the concept of Cohesion to answer questions about "what belongs where". But I didn't understand the conclusion. The author goes through two refactors of a Rails controller. After adding a call to a mailer he says:

> Creating a widget and sending an email about it sound like they belong together, so I would argue this change doesn’t materially affect the cohesion of this class.

Then after adding a database statistic recorder:

> The controller has nothing to do with databases, so this change feels like it reduces the cohesion of the class enough for us to question this change.

Finally the author concludes:

> Yet in both cases, the Single Responsibility Principle has been violated. This tells me that framing the concept of cohesion as the Single Responsibility Principle is absolutely wrong.

How is it absolutely wrong when using cohesion as the paradigm agrees with SRP half the time?