What is wrong with people.
Saying Lukaku should stay because he is our current best goal scorer - apart from the fact that he misses open goals - he is absolutely useless in a team that doesn't have wingers like Perisic, Willian, David Beckham etc etc - without players who cross Lukaku is virtually useless for most of the match.
Considering Martial, Rashford & Greenwood play football in a particular way whilst Lukaku is the only one who plays as a traditional number 9 - then he has to go.
Lukaku needs to score 25+ goals in a season because most if not all of our attack will be directed to him as our one and only finisher. On the other hand - Martial, Rashford & Greenwood can get 12-15 goals each in the best of the season and hopefully spread the attacking duties across a front 3 rather than just one..
Lukaku doesn't fit at United.