For me personally, I prefer it like that.

@freexavier
I enjoy being able to play some music while I am not engaged with other players. I play a lot of Life mods where this is more applicable. With media keys I would be able to play some music while mining for sand or picking crops and be able to quickly pause the music if another player shows up.

Its your preference. Maybe they should have an option to have it disable or enabled. Also my brother use to have some media keys. He always tend to press the sleep button during some tense moments when trying to press the keys he wanted. He actually remove the keys of it to avoid pressing it again.

@freexavier I used to remove my windows keys until I figured out how to disable them while in game :)

I know what you mean. Especially for games that use the Source Engine. Tabbing back into the game takes forever.