Some talented, young players should be traded because they might be worth more in trade than they'll ever be on the field. However, I don't think Senzel falls into that category. My assumption is the Reds believe his bat will materialize. I figure the only way the Reds deal him is if they're seriously worried about his long-term health or if they feel like he's a massive pain in the backside.
I assume if you gave 30 teams of choice of Senzel or Aquino, all 30 would pick Senzel.