Because he's an incredibly talented arm that the Sox signed knowing his age, knowing he'd have to ramp up in the DSL. Even last year, he was still league appropriate age for the levels he pitched. He had an injury, got to the mound, and then the Sox kept him on an innings limit and he still mowed batters down.
He'll be in Birmingham at 23-years-old, which is age appropriate for a high level prospect.
It's not like a 28-year-old, iron gloved Yermin Mercedes having a hot month and suddenly everyone penciling him in as a core piece.