Yamanaka may be (have been?) an ass, but frankly I'm fine with that. Why? 'Cause Taneda seems to be perfectly aware of this and to have her priorities in order: just like she said, she could have thrown herself at Yamanaka and not be rejected anytime she wanted, but she knows she wants to be desired for her to be fine.
I really like characters that know what they're about and are aware of what will and will not satisfy them, and Taneda is certainly one of them: she's been honest with her boyfriend, but most importantly, she's being honest with herself. And that's great imo.