The trouble with zeppelins is that unloading is difficult. Every lb of weight removed from the Zeppelin is another lb of lift that has to be offset. So you have to do things like pump water into the zeppelin as people or cargo disembark. Ships also face this problem to an extent (unloaded ships are unstable) but they are sitting inside a functionally infinite pool of water they can pump in & out.

Zeppelins are tres tres romantique, though.