It's because this is recommended way by ORM creators.
But if you want to change this behavior it's a pretty easy thing. Please check following link https://help.skipper18.com/expert-usage/customization/extending-templates/
where you will see how to customise new object templates. Especially feel free to check section Naming Styles and #CFU/#CFL switches.
What you're looking for is #CFUs or #CFLs depending on your needs.
You can customise this directly in Skipper configuration file but such change will be rewritten with next Skipper update. Or you can create your own extending CFG file which will be kept with next updates.
More about configuration files you can find here https://help.skipper18.com/expert-usage/customization/configuration-files/. You can store custom configurations in Skipper installation folder, user folders or project folders.