The juvenile sea squirt wanders through the sea searching for a suitable rock or hunk of coral to cling to and make its home for life. For this task it has a rudimentary nervous system. When it finds its spot and takes root it doesn't need its brain anymore so it eats it!
The great enemy of clear language is insincerity. When there is a gap between one's real and one's declared aims one turns as it were instinctively to long words and exhausted idioms like a cuttlefish squirting out ink.