I don't know about you but i just have a nightmarish vision in my head of thousands of self - propelled incendiary devices flying around and setting cities and countrysides ablaze. Shudder. No thanks.

And your comparison of zeppelins to cars and planes is flawed. The former consists chiefly of an extremely flammable gas. Protecting it is a thin layer of canvas (which can also burn). The latter contain a relatively small container of liquid which is protected by layers of solid metal and foam and all kinds of valves.