Question #6: Why is some music so underrated but really awesome?

Okay so whenever I watch Grey's Anatomy or Pretty Little Liars I hear a song in the background and I think that I actually like it, so I search for it on YouTube and I find that it's so totally awesome and I've never heard of this artist before so I don't understand why even though this music is on popular tv shows its not popular. I mean singers like Andrew Belle or Katie Herzig should have more people listening to there music, because it sounds so great and it's pretty relatable. I really do wonder why? Anyway so I'm just gonna write a list of songs that are awesome but very underrated.

• Andrew Belle- In My Veins
• Katie Herzig-Way To the Future
• Andrew Belle- Signs Of Life
• John Gold-Vampires Kiss
• Garrison Starr- Upside Down
• Jordyn Kane- Terrified
• Brandi Carlile- What Can I Say
• Birdy- Terrible Love (The National Cover)
• Au Revoir Simone-All Or Nothing
• The Cardigans- Live and Learn

That isn't a really long list but there are other songs, I hope you like how these sound.