The reality of the Scala community is that most of the major players (the Typesafe side) prior to commercialising directly were hoping for some level of popular adoption with devs that would bubble up into startups/SME and for whatever reason that hasn't happened. So now they are banking on the idea they can sell directly into large enterprise space as a one size fits all approach that involves cross training developers (as there are very few out there due to the mentioned lack of adoption). This is pretty risky and needs momentum that can easily be killed by negative stories.

A lot in the original email is correct (I can't speak for the performance stuff as my skills are more webdev side of Scala), especially the way that libraries/OSS projects/sbt pan out. Something like Dispatch that is a fantastic tool and should be simple is a mess of functions-as-operators and poor to no documentation or examples to the point where for some things even reading the source code is not a lot of help. I'm not going to type out my thoughts on the shambles that was the sbt rewrite at 0.10+... just complete madness.

Evangelists sold a bills of goods to non-technical managers. Can't be letting something silly like facts or criticism get in the way of putting a pet language choice into production.