The hero in the book is a man stubborn to refuse any adaptation. In an ideal situation he meets the ideal partner.
But may situations are not ideal. And also I don't see why somone who will try to adopt should be less. It's an awkward ideal " no adaptation". With cognitive dissonance and dissonance reduction you might want to call this "having principals".
Biologically speaking creatures who don't adapt will have to be very strong to survive. Of course many people have all kinds of fantasies about this kind of strength.
-- Updated May 27th, 2016, 6:01 am to add the following --
Leon wrote:But may situations are not ideal.
May = many.