It's actually a misconception that most new machines don't need oil. The manuals are poorly written when they say that they don't need oil. The assumption in the manual is that the machine will be going in for regular service where a technician will oil what needs to be oiled during the service. Unfortunately, when people read that it doesn't need to be oiled, they often think "Yay! My machine doesn't need to go in for service!" This is NOT true. If you're not oiling it, and I can bet many people don't want to get into the places where some of those oil spots are on their own, it NEEDS to go in for service.
Now, as to noise being the indicator of when a machine needs oil. We oil machines to reduce friction on metal to metal parts. This reduces wear and damage. When your machine is getting noisy, it's past the point of wanting oil and parts are wearing on each other. Don't wait for your machine to scream for help. Give it some preventative maintenance (oil) and clean out the lint while you're there! The lint wicks oil and to a certain degree grease away from where it belongs and causes premature wear that may not be covered by warranty.