Ah yes, the age old "insult the others intelligence to feel superior" arguement. Did you even listen to the advert at all? The Titan is super cocky and brave throughout the whole thing, fearless. That's the characters tone. Sure the mood of the set is dark. But as I said, the Titan shows no fear while on the ship...and he chose the music, so the music matches character tone, rather than atmospheric mood. He's just blasting enemies left and right while blasting a song of his choice. Much like many of us Guardians do. It's an ad, it has to be quick, catchy, and memorable. That's why companies have jingles or use certain songs. If you ever hear the song from the ad anywhere else...you'll remember the ad, and Destiny. That's why ads almost always have a song, jingle, or slogan. To be remembered. It's a psychology thing, and it works.