One detail mentioned in the article I was not aware of:
Egypt also earns money from the Palestinians who leave, as they have to pay for the trip from Rafah to the airport. To pass through Rafah, they must present a plane ticket for the day of their arrival, and they are not allowed to stay anywhere in Egypt except the airport.Since Gazans who try to leave via Rafah have no idea if they will make it onto a bus - only a small percentage do - showing a plane ticket for a trip they might never make seems like a huge burden.
What this effectively means is that the only people who can leave Gaza are those who are rich enough to bribe Hamas officials to guarantee a spot that day.
Egypt hates Palestinians so much that they do not let a single one stay overnight.