Not really sure. The weight of the early parachutes for a crew of 40-50 was probably one reason…..plus, I’m sure they were worried about what sort of reception they would receive if they did parachute into Britain from a zeppelin.

Bombing of civilian targets was seen as piracy…..they would probably have been lynched!

Germans had real problems with material for parachutes. Still had them during WW2.
And chutes were seen as effeminated and cowardly till late in the war.

Lynching – I don’t know. Maybe when freshly caught, probably not.
http://www.essex.police.uk/offbeat/o_mu_20.php
Btw, Zeppelins were not only lost in the West, but also on the Russian front and down south on the Balkans.