Let's not also forget at that time Stephen Drew was not only relevant, but also very good. Coupled with Bogaerts, they aapparently liked their shortstop situation not only at the time, butalso going forward. One could argue they traded a ffuture piece for a ring, hardly an uncommon practice.
But really they liked Bogaerts as an all-around player better than Iglesias. Bogaerts was never really in play for the future at third. He tried it and reportedly was very uncomfortable. The decision to force him there to accommodate another equally unaccomplished player wasn't going to happen. It's not the same as moving Betts to the outfield to accommodate a former MVP knocking on the door to Cooperstown.
At some point in the future, Bogaerts may have to move to third. That won't be an indictment of trading Iglesias, either, but more likely just a player aging out of a premium defensive position.
And Sandoval, disappointing as he has been, may not be the direct fallout here many believe. Free agents are not only acquired to fill gaps, but also as PR - a message to the fans and ticket buyers that the team is willing to spend to win. Certainly every GM is aware of the high risk and rate of failure associated with these types of contracts. But they are also aware that big name players, like reigning World Series MVP, can generate a lot of interest after a bad season. The Sox were clearly going to make big moves, so unless Iglesias could have kept them out of the cellar in 2014 (not likely as I believe that was the season he missed), the Sox were going to spend. If not on Sandoval, possibly on someone equally disastrous....