Going to a station is less convenient than plugging in at home. People will use the battery only for most of their driving, especially if the battery range is more than 50 miles or so.
This was my initial thought, too. But I doubt there will be a "use no H2" drive mode in a fuel cell car?!
So if the car uses a bit of H2 anyway, it will run out of H2 eventually. Can it keep going on electricity? And continue doing so, provided it get's plugged in?