Like everything else, there are good uses and bad uses. (Indeed, my objection to the OP was the very black and white nature of it)
Repeating what is already in the app? Not such a good use.
Dwelling on the negative? Not such a good use.
Bringing out something positive that would otherwise not be there? That could be a good use. (Johnny Mercer gave some good advice here: Ac-Cent-Tchu-Ate the Positive)