@Doctor
Think about it this way:
This game was, in fact, originally made for children. The children that do play this might want to adjust the volume and not know how to download or use some program from the internet.
Oh yeah, and I've wanted this feature for some time now. Definite support.
I can't even remember the last time I played a game with YT music running and I WASN'T overrun by ROBLOX's sound effects...