Reading OD&D from cover to cover: Abilities versus attributes
Why is this so?
The word "attributes" has a far more limited meaning than "abilities". Attributes are some characterizing marks of the characters you are creating. Abilities are about everything the character can do.
So this implicitly answers the skill system discussion: While I personally am a big fan of skill systems in xD&D (and love the way they were done in AD&D 2nd Edition) OD&D here is very clear to me: Your abilities are described by the six ratings that you roll for. Everything else is made up by the referee, your characters background, etc.
So 'The Fantasy Game' will revert to calling them abilities instead of attributes and there will be some handwaving comments about how to handle specialized abilities (everything from siegecraft to carpentry).