[tel]

Slow compilation, many ways of doing things instead of a well-defined Scala-style, inheriting lots of Java libraries and having their perhaps very un-Scala-like behavior littered all around, two communities of programmers (roughly) the Java-alikes and the Haskell-alikes

[justthistime_]

How is slow compilation an "academic feature"? Same for the rest?

There might be valid criticism, but to me your comment doesn't make a good job bringing the "stretch marks" across ...

[tel]

The stretch marks come from bringing a small academic endeavor up to "production strength", not that there are specific academic ideas.