Same thing it says about Hillary. The Democrats haven't been able to nominate someone likeable since Obama.
I'm not convinced about the likeability being such an issue. I voted for Bloomberg for his second term, despite being disgusted by him. And even for his third term, there was no viable candidate running against him.
Deblasio isn't likeable by any stretch of anyone's imagination, but he won twice because he was on a certain ticket with no one competent running against him. The NY republican party must be the most incompetent political organization.