So, a single fuel pump failed, which probably wouldn't stop any plane, and then a windshear event? I don't get it.

There are a zillion ways to crash a plane. The two most common are flying a perfectly good airplane into terrain (CFIT... controlled flight into terrain); usually getting in clouds and losing visibility... and continuing on until crunch time. The recent Senator Ted Stevens crash in Alaska was probably this.

The JFK, Jr. crash was a loss of control when the horizon disappeared over the ocean at night in marginal visibility. The plane banks one way or the other, and is not corrected by the pilot because he can't see a horizon (and doesn't know how to follow the instruments available to him). Then, when the airplane starts descending, the pilot pulls the controls back, which at this point, does not stop a descent. Instead, it tightens the descending spiral... until crunch time.

The other popular way to smash up a plane is running out of gas. Instead of a fuel pump failing, perhaps a misfueling / fuel leak would be more believable. Leaving a fuel cap off on some airplanes can siphon the fuel out. The pilot might not notice right away, but then there's almost always two tanks. A fuel line breaking will pump out plenty of gas.

This actually happened to me in my trusty Cessna Cardinal, IFR over the mountains of western Montana at 13,000 feet. The engine quit. I switched tanks, engine restarted, and I landed at nearest suitable airport.

For a windshear event, sure, you can smash up a plane just fine. Maybe some fuel issue caused this pilot to go to an airport that he hadn't planned, which had bad weather, and a combination of worrying about the fuel issue, stress from whatever, getting the crap pounded out of him in the weather, and not recognizing the shifting of wind with enough warning to power out of it. Bang.

Ya, I'd buy that.