The scale system unknowingly puts women on a pedestal.
The fact that you even recognize in your mind that approaching a '10' to be different than a '7' is immediately going to affect your behavior towards her. A rating scale is a subtle and unconscious way of putting women on a pedestal and therefore highly-investing yourself for superficial reasons and making yourself more needy. Why you think a '6' is more needy than a '7' is probably because you treat them differently.
If you have to use a scale go with the binary one instead:
A '1' is a woman you’d like to be with. A '0' is a woman you wouldn’t. Why you want to be with her or not, how she looks, whether she’s just OK looking or the most beautiful woman on the planet -- none of that matters. Either you’re interested or not. The rest doesn’t matter.
Well, that's my opinion, you have the right to think how you like.
http://www.laddertheory.com/