Another person completely missing the point.
It's the 'type' of player that Koeman wants to fit the system he plays.
Depay has and never will be an out and out winger. He's a wide forward - similar in that way to Gabbiadini, for example.
His best form came in Holland, with PSV playing 4-3-3.
Koeman wants his sides to play with three quick, energetic forwards who can all finish and create chances.
Del and Lennon are out and out wingers. Kev can play the wide forward role but isn't consistent enough.
People need to stop looking at it with such a black and white perspective. It's not just the player, it's the type of player that fits a style of play that Koeman wants.