`assert(false)` is pronounced "this can never happen." It's reasonable to add a comment with /why/ this can never happen, but if that's all the comment would have said, a message adds no value.
Oh I agree, literally `assert(false, "This cannot happen")` is useless, but ensuring message is always there encourages something more like, `assert(false, "This implies the Foo is Barred, but we have the Qux to make sure it never is")`.
Ensuring a message encourages people to state the assumptions that are violated, rather than just asserting that their assumptions (which?) don't hold.
