Atkins seems obsessed with depth no matter how marginal it is. So in his mind, having a fat DH like Vogelbach in the big leagues while a better player is in AAA to serve as depth makes the team better than having the better player in the Majors and having to find a Vogelbach equivalent to play in AAA. I guess that's not an exclusive trait to Atkins, a lot of GM's do that due to how options work, but he's a big believer in it based on how he's operated this season. There are ways to incorporate the prospects and use the vetrins more to their strengths (ex. platoon Turner with Horowitz, use KK as a 4th OF, etc), but for some reason Atkins wants to live or die with his old 0-1 WAR guys. I couldn't believe Roden started the year in AA given his age, and now it's mid June and he's still there. There's no plan or logic in place at all.
As far as the Buffalo (and NH) guys, I think a lot of them possess a high floor, so that likely helps their chances of contributing to the big league roster. The only one whose floor is a little questionable is Orelvis, but he has big time power, so the ceiling might be worth the risk if he can play defense anywhere in the IF. Not sure a lineup with all of DS, Horowitz, Barger, Jimenez, Orelvis, and Roden would be any good, but I don't think that's a pure tanking lineup either. There's probably enough 2ish WAR potential with all of them to be respectable.