Why is Garnacho actually rejecting Bayern Munich, well maybe he doesn't want to play in Germany and still wants to remain in the premier league. It's understood that Bayern Munich wanted him as reported some few hours ago but he has turned down the offer and said he only wants a move to the Stamford bridge or nowhere else. Wow, his picked Chelsea, it's either Chelsea or he remains at Manchester United.
I think his desire to stay in the Premier League demonstrates his ambition to become a big star in the future. He's still very young, and his performance will reach its peak in a few years. In the meantime, he seems to want to stay with Premier League teams, experience intense match play, and achieve success in Europe. Bayern would also be a great fit for him, but I like that he's determined
He could realize the ambition to become a big star if he went to Bayern Munich, but his considerations were of another kind. He knows that Bayern Munich wanted Luis Díaz so badly and as far as I know, Luis Díaz is playing his position. If he talked to the Manchester United coach and got the promise that he will get his time to play there, it would be high risk for him to go to Bayern Munich and perhaps lose the competition with Luis Díaz and only get a few minutes per game and not many games at all. That is why it is not always the smartest decision to immediately follow an offer from the most competitive clubs. If he wants to play and understands that this is what helps him make the progress he needs to become a top player, staying in Manchester can be his best decision. He is only 21, ample of time to still go to Bayern Munich or others.