This is so dismissive of the experience of people who find it impossible to live with someone who displays the behaviours of OP's partner, whether it's due to neurodiversity or not.
I have ADHD. I also have bipolar. As an adult, it is reasonable and respectful of me to understand that it is my responsibility to acknowledge the challenges this can present to a partner and work on coping strategies that mean I can live as harmoniously as possible with someone I love.
I ensured I pursued a diagnosis, I have tried various coping strategies and I am stable bipolar wise because of medication, which has been life changing.
If I had chosen not to look into a diagnosis, refused to acknowledge the symptoms, refused point blank to try medication then I wouldn't have blamed a parter for saying they couldn't cope with living with me.
Not because I don't think I deserve a loving partner, but because everyone has breaking points and as an adult I don't expect everyone to be able to cope with my behaviour or else accuse them of thinking they're 'perfect' and only want 'perfect' partners.
It's dismissive to accuse people of that. And minimises what it can be like to be the partner of someone whose behaviours may be due to a condition (whether diagnosed or undiagnosed) but are still behaviours that are hard to live with.
I adore my partner. We are a team. We both want to be our best selves for each other and work together to make that happen. If I suddenly stopped making the effort to manage my symptoms or came off my meds and didn't want to ever be medicated again, he might not be able to cope with being in a relationship with me. Not because he only wants someone 'perfect' but because he's allowed to have limits and boundaries too!