i am sure the lady who hadn't got her ddog vac'd is also passionate about animal welfare Addicted - and you come from a vets brainwashing environment so your response is an expected one.
Do MNers get flamed here for offering alternative views, or anywhere out there once starting to talk about this topic of challenging the whole industry and its benefits to our dpets.
Many vets do now acknowledge that animals are pumped with far too many vaccinations (which is a huge assault on a very young immature animals immune system), and many of the over-zealous yearly boostering schemes have been pared back.
I think that probably doing your own research is the way. Animals kept in poor conditions, or overweight, or unfit, stressed will have weaker immune systems as will pups and the elderly. All those animals are at risk of falling prey to disease, as are people.
a puppy raised on a puppy farm for instance, will already have an malnourished bitch supply milk (part of the dog worm cycle) which is infested with worms (eggs). Cat fleas are a problem for dogs, dog fleas pretty much disappeared. The pup will be riddled with worms, get a poor supply of milk, be in overcrowded unhealthy conditions and therefore rife for disease where it will get a hold on those already weakened and something like parvo could wipe the whole litter out and the bitch too.
Care around pups is very specific to protect their environment and in the main vast numbers of well-bred and reared pups will thrive (and they have no vaccinations until they're older). Its not the vaccinations (or lack of) that mean such high numbers will survive but good husbandry. Although there are still relatively common congenital case deaths and pups that just won't thrive.
I know of very successfull working/breeding/show people who have never vaccinated their animals, for decades, and have never lost a litter to kennel cough/parvo, etc. So this is very contrary to what many/most would expect - believing this to not be possible.
The elderly ones, well they all die of something sadly, but mostly now awful emaciating and painful cancers or crippling and painful inflammatory diseases, and most of the blame for this is attributed to diet now and vets being receiving their 'dietician' element of their training from the commercial producers of these foods.
The only way to know for yourself is to review the research [from BOTH sides] and make your own mind up, but, like any sales and marketing machine, most vets will 'sell' you vaccinations 'programs' to keep you coming back. Vets didn't used to be like this but they are far more of a marketing machine now. There are some out there who no longer hold with dried food believing its the cause of massive rise in the terrible illnesses that most dogs die from far earlier than dogs used to die. It just depends on what you choose to believe.
I have a mixture of animals ranging in age from 15 to 1 year old, they all have brillaint white teeth and fresh smelling breath, something i'd not experienced [in my pets!] till starting to challenge for myself today's routinely followed 'regimes' advocated by vets. Previously my animals regularly had dental intervention and surgery for very poor teeth, now people comment on them, and their mouth is just the start of the rest of their body and reflects their health or otherwise.
Did ddogs/cats die younger generations ago, or live longer and die of different things?
Ask around, look for yourself, make your own decisions (but mostly people are very scared to flout the scare tactics of the medics - that your danimal will die the most horrific death and you will be letting them down if you don't do as prescribed - but todays manufactured illnesses are just as devastating and far more costly and difficult to support and very often resulting in years of suffering all round.
Its difficult to make such a big decision about your animals llife and with little access to the relevant experiences/information you can only fall back on what you think best for your own animals.
good luck with your investigations, be very interesting to hear other views and reasonings for choices here.