I figure they brought him up because they know the Sox aren't going anywhere this year and he can get a good bit of ML experience when it's not gonna matter a ton. A few months ago I remember reading in the ml threads that scouts were saying that his bat would play in the ML right then. He has done nothing to disprove those comments and there's no time like the present to get him established.
As for the "this day, that day" bullshit you're arguing, c'mon.
As for the "this day, that day" bullshit you're arguing, c'mon.