To be clear, Mercurial does not have a staging area, but it does have allow selective commits (and selective uncommits) via prompt-based or interactive UI selection of hunks. Disagreeing with the need for a staging area is not the same as saying selective commits are unnecessary (I use Mercurial more than git and I rarely commit everything in my working directory in a single commit - I like small commits).
That makes sense, thanks for clarifying!