To reproduce, simply create a new Maven project. The folder src\main\resources isn't created.
If that folder doesn't exist, there's no easy way to create a resource (I don't consider going to the Files view & manually creating the folder to be easy).

In my opinion, the best solution would be this: when creating a new file in the project root, NetBeans checks the kind of file, and automatically puts it:
- under Source Packages (src\main\java) if any kind of .java file is created
- under Other Sources (src\main\resources) if any other kind of file is created

This solution would immediately also solve another issue, namely that currently, if you create a file in the project root, it won't show up in the Projects view & you have to go to the Files view to move your file somewhere else manually.