Postgres LISTEN/NOTIFY does not scale

The article is good, but maybe a bit negative on the postgres feature. I think the article reads much better with the slant:

  "LISTEN/NOTIFY got us to this level of concurrency; here's how we diagnosed the performance cliff, and here's what we're doing now."

Which is like... cool, you were able to scale pretty far and create a lot of value before you needed to find a new solution.