The alien milking scene did kind of stick out like a sore thumb (or nipple) in The Last Jedi, but just as many Star Wars fans who have bashed the movie, have also praised it for the changes that Rian Johnson brought into the franchise.
Mark Hamill discussed these emotional changes that Luke underwent for The Last Jedi in a new interview, even questioning the changes.
Many Star Wars fans were angry to see the way that Luke Skywalker changed in The Last Jedi, going from seeing the good in almost everybody, including Darth Vader, and then deciding that he has to take out his nephew one night.
Hamill knows the character of Luke Skywalker better than anyone, except for George Lucas, and expected something else when he hopped on board The Last Jedi.