I agree, just as much as mixing doesn't. Vision and songs are what makes it timeless.
However, that was actually a quote from the band so don't lash out on me for it.
Comparing mixing to mastering in any way is ridiculous.
Take "Born In The USA", and turn down Springsteen's vocals until they're entirely buried by the guitars, then tell me the song is still timeless. I don't care how clear the vision, production, songwriting, etc. is, if it's not mixed well, and if the levels aren't right, no one will listen to it.