With all the respect to the pilots i think this was a typical scenario of the tendency to dive for the lights once you have them in sight. I've seen it before and believe me if you don't place it in your mind not to do that beforehand then its very tempting to go below the G/S in poor visibility. I remind you that in 500m vis or thereabouts, the 1st thing you see is the approach lights so going towards them is your natural instinct. I think they realised but slightly late.
But then again thats my opinion and i could be wrong.