fall by the wayside

(idiomatic) To fail to be completed, particularly for lack of interest; to be left out.

Example: 1611, Bible (KJV): Mark 4:3,4 (Parable of the sower)
  Hearken; Behold, there went out a sower to sow: / And it came to pass, as he sowed, some fell by the way side, and the fowls of the air came and devoured it up.