NPR had a segment on this the other day. They make sense for very specific circumstances - like folks who have lived in areas where property values have been skyrocketing, and they are sitting on over a million dollars in real estate, but are cash poor. Essentially, letting them tap into the home value they acquired via inflation to fund their living.
But of course, we all know that reverse mortgages are mostly used for older folks who may not have living heirs, and who also may not be totally cognitively there.