Why BA is so important?

Let's see, if there is a bug/mistake in code due to developer's whatever mistake/error/unawareness, and the code is in production. To fix that, let's assume the effort is X man-hour or dollar; but if there is a bug/mistake in design, it could be easily cost 10X; and if there is a bug/flaw in archtect, it could be 50X; if there is a critical flaw in requirement (which is BA's work), the cost could be 500X, different order of magnitude. If the reqirement is completely not what business want, all the king's men and all the king's horses would not be able to put that Humpty-Dumpty IT project back :) You got to get another hen (BA).