It has been several times that I have lost a member because they have no control over who can comment on their personal photos, nor can they delete a comment they dislike.

Correct me if I'm wrong, but currently the only way for a member to delete a comment is to use the admin. When I explain this, the answer is often: "Well that's a shame, so I'm leaving the site". What I can understand ...

If there is a way to fix it, I haven't found it ...

Personal (portrait) photos are special objects, I think it was a mistake to treat them like everyone else, because you will find stupid comments at best, derogatory comments at worst.

A solution for this?