I think it speaks to how people respond to receiving truth and knowledge. It speaks in metaphor about how people either choke out things that challenge their worldviews, grab hold of it quickly as some new fashioned truth to follow looking to it to give them quick easy Answers with a capital A only to fall away when it doesn't give them the fast path to enlightenment, or those who instead consider carefully what is heard and received and allow it to grow and transform their understand and their lives.
Now I want to add something here to be clear. I think this applies to any source of truth and knowledge like this. Metaphorically speaking, the "word of God" can be from anything. Such as from science. So the religious who stuff their ears when science reveals how evolution has formed and shaped all animal species on the earth, they are in my opinion directly rejecting "revealed truth". They are rejecting God, in effect. They are the ground overrun with weeds that choke out truth from growing in their gardens. The weeds in their case are the symbols of their religious identities they cling to out of fear a sense of security that they let choke anything but the familiar. It can also apply to anyone anywhere else in a belief system as well where they refuse to let anything in that challenges their system they have constructed around themselves. It goes both ways, to the secular who cling to science as the Answer, and to the religious who cling to their religion as the Answer.
Of course there are other metaphors one could come up with and not just these three, but the point is these are metaphors, and metaphors are figurative ways to describe the way things work in general, easy to grasp pictures. Taking them literally is to miss the point utterly.