If you want to learn to play the guitar, learning easy guitar songs is one of the best methods of advancing your guitar skills. The logic behind this fact is pretty simple and straight forward, yet many guitar teachers neglect it for some reasong. The dream of all beginner guitarists is to play songs. This is evident, it's why they start learning the instrument in the first place.
However, playing the songs you want will require that you be familiar with given guitar techniques, and have mastered them already. This is the harder part of the equation, but it's a fact. You can't rock out until you know how to. Of course, learning the techniques required to play the songs you like will mean you have to practice them beforehand. Unfortunately, you can't just pick up a guitar and be able to play it without months of practice.
This is the point where many beginners actually quit playing altogether. They get bored of all of the technique exercises, the chord shapes, etc. And this is the point where learning by playing easy guitar songs come into focus.
All beginner guitar lessons should concentrate on 2 things: