I understand how permissions can be granted and revoked, owners changed and so on. I'd like to know if the groups' or others' attributes matter at all when I am the single user of a desktop edition (Ubuntu). Couldn't the permissions by default be just -rw------- and -rwx------, that is 600 and 700? What's the point of granting r,w, or x to group or others, when you are not running a server? 
Users, groups and others in a single user desktop installation
permissions;learning