Based on what?
Because Keane didn't have a good season last year and Holgate had a decent few games.
Keane won young player of the year at Man U ahead of Jesse Lingard, 4 England caps, around 100 prem appearances, nominated for PFA young player of the year in 2016/7.
Doesn't sound crap, he was just one of many in our squad that had a poor season last year and deserves a chance in a settled team.
Why did Man U get shut of him and keep Lingard ?.
Answer - Because they saw that he was as good as he was going to get, where as Lingard would keep improving ( debatable I know ). Then punted him to Burnley, where he found his level in a deep lying back four.
He`s not capable of playing in a high line, due to his lack of pace and mobility, where as Holgate is.