The reason that fuel cells are not viable is because unlike batteries fuel cells are not an energy source. Batteries internally store energy in the form of electricity from an external charge. Fuel cells do not store energy, they convert fuel into electricity. Fuel cells solve NONE of the current problems of our fossil based system and introduce additional issues;

1. Fuel for the fuel cells needs to be created, usually from fossil fuels, or water + electricity = hydrogen. The energy to do this - electricity needs to come from some source. Coal, Nukes, and gas fured plants produce enough spare electricity at night to make hydrogen.

2. Fuel for the fuel cells needs to be transported usually by tanker or truck - this uses fossil fuel. It is inefficient when compared to the existing electric grid. Electric distribution will only get better as smart grid and low loss super conductors are installed on the grid.

3. Hydrogen fuel distribution systems need to remain under pressure, and never leak. Remember Hydrogen is explosive. They will need to pump the hydrogen into large underground insulated tanks or above ground insulated storage containers. Those cost big bucks. And then hydrogen is pumped  again (never leaking) into personal automobiles and trucks, this pumping needs to be under high pressure, to store enough fuel on board to allow reasonable travel distance.

4. This on-board storage, needs to be under pressure, and cold, very cold (-160'). This is not available / affordable technology. The only way to achieve high enough pressure is to super cool the fuel and the tank - this again uses energy constantly.

5. At every step in the manufacture and distribution and storage and consumption of fuel for fuel cell transportation, there are energy losses, brought about by the conversion or transportation of this fuel.

When you look at the electric grid as a potential fuel source, powered in part by renewable energy - and the inherent efficiencies of battery electric vehicles, it is a completely different game.

When it comes down to it, once you convert hydrogen to electricity to power your car it costs you 10 to 100 times as much to travel in that car as it would in a simple battery powered electric car.
So
Lets focus funding efforts on making good batteries that are really light-weight.