Hydrogen only has a high energy density by weight, but by volume it's actually quite low compared to other liquid fuels. Then you have all the problems with handling liquid hydrogen, insulation needed, all sorts of additional functions are required of the storage system compared to jet fuel. For example, icing would probably be a problem if the wing tanks are full of liquid hydrogen!
Ice on the outside isn't a problem for the hydrogen. It's the other way round. The weight calculations have to include enough insulation on the tanks to prevent rain from freezing to the wings.
