Clients may have qualities that are attractive, but the therapeutic relationship has its own specific purpose and boundaries.
Once I take on someone as a client, I take on a very particular role as therapist. My aim is to help them with what they are dealing with. There is no expectation that they do anything for me except come to sessions and pay my fee.
This relationship can become complex and deep-rooted, but it exists in a therapeutic context. Clients know me in my role as therapist, not across the other contexts of my life. Likewise, I know them as clients.
I can recognize that someone is smart, funny, charming, ambitious, creative, kind, or sensitive. Those are all attractive human qualities. Recognizing them is different from seeking another kind of relationship, which would violate the therapeutic frame and is not something I would do.