This sounds odd. Does your code never interface with Java libraries and frameworks? I envy you! It's all too easy to forget to wrap a suspect value from Java-land with an Option(..). And cumbersome even if you do remember.
And then, there's the code written by Scala novices who just love using nulls. Yes, yes, "code reviews", we all know they are always practiced all the time :/
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").
As for novices: yes, novices tend to do that. They tend to miss, misremember or fail to put into practice what they should have learned on day 1. I've also seen senior devs who were not exactly newbies (in general) still using nulls because they don't grok Scala; the famous "you can program Fortran in any language". The reality of software development is that you have to deal with all these people.