Why Not Go Anyway?

You might have had the chance to watch it live, but a plane had to make an emergency landing in Boston today. The plane had an equipment problem with the landing gear, and safely landed at Boston's Logan airport. Article here.

But I'm left wondering one thing. The plane took off from Boston, and was going to land in Milwaukee. It was a Midwest Express flight, and they are based here in Mil-town. The plane had the problem right after takeoff, so the pilot had to fly around Boston in a big circle for almost two hours before he could land. They did this as to lighten the airplane to soften the landing by burning off fuel. That part makes sense to me. Plus, all that pesky jet fuel is just a little bit combustible.

But if they were going to fly around for an extended period of time..... why didn't they just fly to Milwaukee where they were going in the first place? Why the need to circle around Boston, just so they could end up where they started? You'd be burning jet fuel on the way here, and the plane is going to have to land sometime, so why not get to where you have to go anyway?

It probably does have a very simple explanation, and maybe Jim will have one for me. If not, I'll be forced to call Sky Dork, and I really don't want to have to do that before the Bears game this week.