I do not understand this logic whatsoever. If you're a rebuilding team like Arizona, Upton would be the first guy I'd build around. Young, high ceiling, relatively cheap long-term contract extension given that he might become.
If someone offers them a baseball equivalent of Herschel Walker where you get a top of the rotation pitcher, a high level position player and a solid bullpen piece or back of the rotation starter, you have to at least look at it. Royals offer them Greinke plus something else, hey, it is a possibility. Odds of it happening are probably low single digits though.
I've still got slots open in the second league if anyone is interested in joining, since first timers have had pleanty of chances to join by now I have no problem with fantasy whores from the first league crossing over and playing.