Yeah but drgs don't really count on the wyvern for half their dmg... in fact just keeping the wyvern alive gives the master a huge boost in att/def and haste so in a way it's even less of a choice since choosing to help your pet stay alive also gives huge boosts both in dmg and defensively for the master. Plus there is the large innate DT and such.
As far as all pet jobs... um what other pet job stays in range? Smn certainly doesn't not with 30 second recast and not having to get that close to begin with. geo can for an extra debuff but often doesn't plus their "pet" also has a huge native dt. Pup can but usually doesn't and besides their pet already has a much greater built in survivability. Notice the pattern all the jobs that are near there pets already have huge built in dts for there pets. So they don't actually have to choose between survivability of the master or pet because the pet will have just as much survivability as the master when the master is in full dt set. Should also be noted that besides bst and drg all other pets jobs have pets that are fairly disposable able to put them back out in short order so they care a lot less if they die to begin with.
tl;dr to make this fair compared to what drg has to do you'd basically need to give the jug a native 30% dt and give them some kind of boost for keeping their pets alive like huge ja haste (which would be a good idea anyways considering they keep pushing fencer on bst and single wielding isn't a good idea for them without some ja haste)