Half-Life was the original game, and in order to play Counter-Strike, you needed to write -game cstrike in the parameter for the half-life executable. Same with all the other mods i'm referring to
But I agree, in that it should not include like minecraft mods, or mods that just alter small stuff ingame - they should be "full fledged", to a certain extent - it should be a whole other feel to the game.
But then again, where to draw the line.. It's a tough nut to crack, indeed!