Well, it sorta depends on how the anxiety or low self esteem manifests itself. If the person is aware of their anxiety and doesn't try to cover it with over-compensation in the other direction (excessive self assurance or arrogance), then it can be rather charming.
Would it suggest that like-attracts-like with mental illnesses? E.g., if you have ADHD, other people with ADHD will be more predictable to you than people without ADHD, so you'll prefer to date them?