Snoring can kill sex in marriage? I'd say its a distant runner-up to marriage itself. Or to wives turning 40. I have amassed a surprising amount of anecdotal evidence of this, shall we say chronological 'epidemic'?
I tell you what, if you are in love with the woman, and you are offering up really great sex, your sex life will not go away.
Maybe she thinks you are old too.
my wife is 41 and is a sex crazed lunatic (who snores very load and weirdly I must say), so I don't know what kind of anecdotal evidance you have, but mine is the smile on my face....
btw I'm 31