Does "he’s a six and he wanted tens" mean "he's gone too far"?

Nope, not even close. A ten is a great looking specimen, either sex will do. On a scale of 1 to 10, he's a 6. He wants a 10, the perfect looking woman. He's gone to a matchmaker who's trying to get him a date with a girl he's compatible with. He's not interested. He only wants to date girls based on their looks and then complains that these girls aren't for him.
Similarly...
A 3 dressed up as a nine is akin to saying you put lipstick on a pig.

http://www.youtube.com/watch?v=u3uH-vamqJg

3 Dressed Up As A 9

by Trooper

Hey wait a minute
Who do you think you are
Comin' on, comin' on
Like you're some kinda movie star

Wearing twelve hundred dollars
D'ecollet'e
You looked a whole lot better to me
From twenty feet away

You're just a 3 dressed up as a 9
You're only, wastin' my time
A 3 dressed up as a 9, hey yeah ...
(All dressed up but you're only a 3, a 3 dressed up as a 9)

Socially
You know you fit in just right
But as for me
I'm gonna have to pass tonight

Well you can say what you like
Be what you wanna be
You can suit yourself, baby
But you don't suit me

You're just a 3 dressed up as a 9
You're only, wastin' my time
A 3 dressed up as a 9, hey yeah ...
(All dressed up but you're only a 3, a 3 dressed up as a 9)

Hey wait a minute
Who do you think you are
Comin' on, comin' on
Just like you're some kinda movie star

Well you can say what you like
Be what you wanna be
You can suit yourself baby
But you don't suit me

You're just a 3 dressed up as a 9
You're only, wastin' my time
A 3 dressed up as a 9, hey yeah ...

Memories... loved this song back in the day.