No, the bad reputation is not overrated. This is the essence of why appeal to authority is a fallacy. Facebook is (or was) largely written in PHP; that doesn't mean PHP's bad reputation is overrated. Many banks run on COBOL; that doesn't mean Cobol's bad reputation is overrated.
MongoDB's bad reputation is well-deserved and based on a long history of misleading (or outright false) marketing claims coupled with poor technical properties (from unavoidable data loss to horrible compaction performance to global write locks). At this point, even if all the known issues were fixed (and they aren't) it would still take a long time for their reputation to recover. Given that some of MongoDB's direct competitors do not suffer from these problems and can largely function as drop-in replacements, recommending people use something else is really the only responsible course of action.
MongoDB's bad reputation is well-deserved and based on a long history of misleading (or outright false) marketing claims coupled with poor technical properties (from unavoidable data loss to horrible compaction performance to global write locks). At this point, even if all the known issues were fixed (and they aren't) it would still take a long time for their reputation to recover. Given that some of MongoDB's direct competitors do not suffer from these problems and can largely function as drop-in replacements, recommending people use something else is really the only responsible course of action.