Some of you lots clearly underestimate the responsibility MAIN strikers have for their respective teams, especially top ones.
The burden that comes with it is huge to suggest that Rashford should be our main striker and be loaded with that heavy responsibility.
He can go on a bit of a run but as soon as goes through a drought, there'll be backlash and criticism from the media. Such pressure becomes unbearable especially for such a young player.
We have Ibra there the better and more experienced striker. He can cope with the pressure and take on the responsibility. And most importantly he's experienced and mentally strong enough to deal with bad patches in form and bounce back.
One can see Ibra getting out of his recent drought, and go on the regain goalscoring form. Something that'll be very difficult for a kid to pull off.
You put Rashford as our main striker right now, he goes on a bit of a 6-7 games drought without scoring, pressure piles up because media and everyone will be saying they expect a United striker to bang in goals week in week out.
He becomes unsettled because he wasn't protected enough by putting such huge burden on him and he starts struggling thus more set backs for him.