I think this reply thread is confusing the specific, i.e. the technique of 'mobbing', with the general, i.e. the (mis-management) approach to fixing issues with 'all hands to the pumps'.
The only thing the Unruly team is dogmatic about is delivering valuable software. The techniques they talk about are simply this - techniques.
In my work as a consultant there is rarely a 'one-size fits all' technique to developing a feature, but knowledge of several approaches is very valuable.
This is the purpose of the article - to allow you to consider the addition of 'mobbing' to your existing approaches of single development and pairing