I think that this accident was based on a lack of experience. I say this because if you are flying in severe ice with an aircraft that uses boots to shed the ice, it is not the same as on an aircraft that has a heated wing. Those boots can't keep up with the build up of ice if it is severe. I have many hours in the King airs, and any time I was in icing conditions, severe or light, I never changed the configuration of the wing, this is something that I feel the crew should have taken into consideration, when you are that low, and picking up severe ice, its better to not change the configuration, land at a faster speed, BUF has a long runway, I doubt that the dash-8 would have used up the whole runway even at 0 flaps. If you do some research, you will find many accidents that happened due to the crew changing the configuration of the wing, were if they just left it alone, they would have made it.
I think the only people who have mentioned "severe" ice is the media.