The main issue right now is infrastructure. For starters (and I could be wrong, so don't quote me), I believe all of the stations only exist in and around California. I do believe that is the only state Toyota offers that car for sale. Even then, I've read of station refill issues. Once you can find a hydrogen refill station, I've heard of people showing up and the station is completely out of hydrogen. Now you're tasked with having to go find the next one. Also, there are two kinds of pumps, and not every station has both. If you have over a half tank of hydrogen, you need a high pressure pump to fill your vehicle. Not all stations have that. It's also expensive. I've read of $100 - $200 fill-ups. So now you're driving a vehicle that has limited fueling stations, is expensive to fill, the station you find might not have the right pump, or they may not even have the fuel.
With all of that said, I heard Toyota is trying to work with state(s) on the infrastructure. They're also offering a $15k hydrogen fuel card with a purchase of their car, the Toyota Mirai. If we can get all the kinks worked out, it's a fantastic concept. Hydrogen is the most abundant element in the universe and the byproduct of running a vehicle with it is water vapor. Not much to dislike there.