What the author is alluding to is that centralized messages queues can cause catastrophic failure over[1].

Industry knowledge of how to distribute loads has improved significantly in the past 10 years. I wish the author would touch on some other options like using a load balancer with consistent hashing[2].

[1] http://martinfowler.com/bliki/CatastrophicFailover.html [2] https://en.wikipedia.org/wiki/Consistent_hashing