People aren't dissing the hydrogen fuel itself so much as the pie-in-the-sky claims that it will solve every energy problem known to man.
A small hydrogen fuel cell may eventually power homes and get us off the grid.
Yes, one of them may eventually do just that but it's going to take a major technological breakthrough or two to make that possible.
Yes, but where do you get the hydrogen for that fuel cell?
That's right...from LP (liquid petroleum) gas or natural gas. That's what GE's home fuel cell unit runs on.
Hydrogen is not, and never will be, a "fuel." "Fuel" is something that contains more energy than it costs to create, and until we discover deposits of molecular hydrogen in the ground, H2 will never meet that standard. Hydrogen is a battery, a way of storing up one form of energy for more convenient use later.
The only thing a "hydrogen economy" accomplishes is decoupling energy consumption from energy production—in other words, since any form of energy can be converted economically into hydrogen, and any form of work can, once a hydrogen distribution network is established, be performed economically with hydrogen, a hydrogen economy lets us pick the most efficient methods of both production and consumption.
The dirty secret, though, is that far and away the most efficient method of hydrogen production is nuclear power. Now I, for one, am 100% behind nuclear power, so when people say "hydrogen" I say "bring it on!" Your typical hydrogen enthusiast, however, hates nukes even more than he hates fossil fuels, so I'm really at a loss to explain hydrogen's popularity.