If this was NFL or NBA, sure. There is a way more likely chance of getting a franchise changer like Andrew Luck or Anthony Davis in the top 5, while there is way more likely chance of getting a Blaine Gabbert, Christian Ponder, EJ Manuel or Alec Burks, Austin Rivers,Tyler Hansbrough type players in outside the top 5. I can say as a Wizards fan that the Wizards tanking for a few years in a row to get John Wall, Bradley Beal and Otto Porter completely changed the franchise around. It was a clear tank too, half the guys the Wizards were starting aren't in the NBA anymore. Another perfect example would be the Colts, they definitely tanked that season to get Luck, there would be no other reason to start Curtis Painter that long otherwise and it worked out for them.
In the MLB, it just seems there is a ridiculously high bust chance for guys. Sure every once in a while there is a can't miss prospect, but the next Bryce Harper could also be the next Drew Stubbs or Tim Beckham.
The Sox are already loaded with young talent and have an extremely deep farm system. I would rather continue seeing this team play well and have these young guys continue to develop and gain confidence for next season than have these guys tank to potentially get a good draft pick that may or may not pan out. This team has actually been enjoyable to watch the past month or so.