Utilizing branches heavily does not imply that you shouldn't have a single mainline branch that branches are merged down to often. In fact, it's incredibly difficult to do continuous integration and deployment effectively without branching. Continous delivery requires that your mainline codebase is pristine and ready to be deployed immediately. Without the ability to make commits that don't affect that mainline, that's an unrealistic expectation.

I would say the authors probably have an issue with long-running branches, especially where communication between the mainline and the branch is sparse, but short-lived branches have a ton of benefits if you're deploying continuously.