No doubt those who heard this parable, especially the disciples who were fisherman, knew exactly what Jesus was talking about when he spoke about a dragnet. Once the fish were brought to shore, a judgement would have to be made about the fish. Which one’s made good eating and which ones did not! The good ones would be collected and the bad ones were just discarded as being of no value. Jesus simply says that this is how it will be at the end of the age! The angels will come forth and separate the wicked from the righteous.