Unable to open a folder that contains a . in finder
They are still folders, just packaged. You can right-click the folder and choose Show Package Contents to show the contents of the package.

If you want to permanently set .service packages as not assigned to OS X so they're normal folders, you can remove item 257 from…

/System/Library/CoreServices/CoreTypes.bundle/Contents/Info.plist


Note that editing this file incorrectly can break many things. Be careful and have backups.