The LW's relationship is doomed. She will always feel like she is "settling". Once that idea is in someone's head, the other partner is forever given second-class status until someone with all the same qualities AND the missing quality comes along.

I have nothing wrong with someone saying they want someone more intellectual. Just like wanting someone of the same faith is important to some. Or the same race. Or tall. Or short. Other folks don't have such rigid rules for dating/mating/partnering. No biggie. Everyone is different. However, out of respect to the LW's partner, she should tell him of his "flaw" for her and then leave.