From the Post-Gazette's Q+A today:
A final point: [Delwyn] Young is about the same age as Moss and [Andy] LaRoche, so it might be seen as thoroughly puzzling that management is not giving this player the same chance. (His start last night was his first.) He has quite the pedigree as a hitter, and he has done nothing to dispel that in his severely limited opportunities with the Pirates.
Although the Dodgers' management team isn't exactly the sharpest in the shed, why would even they have traded a player with such a "pedigree" for players to be named later, which usually roughly translates as "bupkis"? The answer is that Young just doesn't have "quite the pedigree" if you understand things like minor league statistics, park effects, and age relative to league. It's no accident that LaRoche cost much more to acquire and has been all over top prospect lists for years, while Young barely rated a mention. Young has not received the same chance as LaRoche and Moss, and this is as it should be.
First, Young isn't about the same age as Moss and LaRoche. He's over a year older, which doesn't sound like a lot but makes a big difference in baseball terms. Young was humming along decently as a prospect until he played his first full season in Las Vegas as a 24-year-old and hit .273/.326/.457, which is terrible. Rule of thumb: offensive stats in any minor league park in the desert or the mountain West have to be viewed carefully. Las Vegas is one of the best places to hit in all of professional baseball, and Young's .783 OPS that year placed him behind such luminaries as Jeff Duncan and Joel Guzman. (LaRoche, in comparison, had a .950 OPS at Las Vegas that year despite being younger and not having played at that level before.)
Since then, Young has received most of his at bats at Las Vegas, and while he's hit well, a guy in his mid-20s who doesn't field and is repeating a level at one of the best places to hit in the minors had better hit, or he's not even going to have a job in the minors for long. Young was probably a hair more interesting than the typical overaged minor league slugger, but only a hair.
Not only did LaRoche hit better than Young in the minors, and at younger ages, but LaRoche has been a favorite of prospect hounds and scouts for years, and he's a credible defensive third baseman. And beyond just OPSes, his statistical profile is more interesting than Young's. Young is a well-rounded hitter, but he doesn't have any exceptional skills--he has a little bit of power, his batting averages have been decent but not great, and he draws a few walks. LaRoche, on the other hand, showed exceptional control of the strike zone in the minors, walking almost as often as he struck out, which suggests that if given time, he has a better chance of developing his other skills (power, contact) as time goes on.
Think of Jason Giambi, who broke into the big leagues rather late and didn't hit a ton of homers in the minors but became a monster hitter when he got to the majors (with the aid of performance enhancers, but still). GIambi showed great control of the strike zone in the minors. Brian GIles' career started in a similar way. Just to be clear, those aren't terribly likely outcomes for LaRoche, and I'm not saying he'll turn into the next Giambi or Giles. But there's still the possibility that he'll be a lite version of those hitters, which would still be extremely valuable. Which is why PECOTA (subscription required), for example, compares LaRoche to Giambi and sees a meaningful chance that LaRoche will develop into a superstar, and almost no chance that Young will. LaRoche and Young are apples and oranges.
Young is a lot more similar to Moss, since Moss also lacks one outstanding skill as a hitter, but this is a case where little things matter. Moss is over a year younger, he's probably a better defensive outfielder, and while his AAA stats superficially look less impressive than Young's, he posted them in a park and league where it's much more difficult to hit. Moss' power potential is thus better than Young's, so there's a much better chance he'll break out and emerge as a solid regular or even a minor star. I'm not saying it's a particularly good chance, just that it's much better than Young's.
I like Young just fine, by the way. Although I thought the Pirates' obvious crush on him was a little bit weird, he's a nifty bench player to have around. But that's all he is. Suggesting his "pedigree" is anything like LaRoche's is absurd, and he's not nearly as interesting as Moss either. If the two of them weren't around, sure, there would be no harm in giving Young some playing time to make sure he's just a bench player, and he probably wouldn't embarrass himself. But he doesn't have the upside that LaRoche or Moss have, and it would be a mistake to play him in front of either of them.