IntelliJ doesn't have the Scala plugin installed by default. However, that is true that you could combine the 'Install IDE' and the 'Install Scala IDE plugin' steps by installing the Scala IDE.

Even if you do combine those steps, there are still further steps a user would have take after they install everything. You described the set up as just being as simple as "Push the button, choose the scala template, give it a groupId and artifactId, done". However, I don't think it is that simple. As far as I'm aware, no IDE will give you a Scala project with a Maven POM. You can choose to create a 'Scala project' or you can create 'Maven project'. You can't create a 'Maven Scala project'. So you will have to figure out how to add Scala support to Maven manually. Also, you may have to figure out how to let your IDE know that your project is both a Maven project and Scala project.