The Scala landscape is very, very quickly creating their own libraries for similar popular Java libraries/frameworks. It is entirely possible to create an application, web or otherwise, that uses no Java libraries at all (save for the sbt dependency tree).

As for "Scala novices who just love using nulls", if you're seeing that, then the coder in question missed day 1 of Scala training, which is always "if you are writing the word null, you are doing something wrong" (right up there with "if you are writing the word var, you are probably doing something wrong").