Pop/Rock music is always defending itself/creating excuses & making reasons why it should be heard. Ambient music does not have the goal of attempting to sell more records nor does it seek any sort of popularity. In fact, its passive nature and ignorableness, coupled with its desire (on even the most extreme levels) to create sonic architectures and soundscapes, is what defines it.

I may have defined this point already… understanding ambience or ambient theory is based on the knowledge of its source. That is, to understand purity in all things, specifically sound.