I was already a history freak before I got hooked on Civ, so I haven't really learned much new through it. Of course, the historical twist of Civ is a very interesting part of the game and helps to keep my Civ-addiction too strong...
That said, I think Civ functions similar to other strategy games, only perhaps better, in that it can develop some strong strategic thinking skills, especially when played at the higher difficulty levels. I can see business training applications because Civ teaches attention to detail, necessity of efficiency, economies of scale, creative problem-solving, and long-term strategic focus. It also can train someone how to do business modeling, making projections like "based on how we go with this decision, what are the potential ramifications to our empire (business) 50 turns (6 months) from now?"
I mean, shoot, tons of the top players use Excel spreadsheets to chart out the most efficient empire growth decisions! I've gone that route in my own games and have seen my gameplay skills increase dramatically. More importantly, as I'm now at a job-seeking stage in my career as part of the Finance profession, I know many employers desire applicants with strong business modeling skills using Excel. I can honestly say I think Civ has helped me a bit in that area.
Of course, I would never claim that Civ is an all-encompassing business training tool, nor one that people should spend tons of time on. Civ has tightly controlled variables to deal with; RL is much more complicated. Civ is tool only, but I think it's a pretty decent one.
The trick is to just remember that living is much more important outside of the Civ universe than inside it.
