I don't think the team did him any favors by setting expectations really high. Nor does it help that you have Jeremy Pena and Julio Rodriguez (among others) out there performing pretty well as rookies. But at the end of the day, he's still a 22 year old in his 15th month of professional baseball.
I expected better of course, but people should have always been open to the possibility that he would struggle or that there would be a learning curve adjusting to big league pitching. And not every kid hits the ground running out of the gate. Aaron Judge and MIke Trout are good examples.