Hybridisation or any other of the factors in captive breeding, doesn´t worry me because of conservation issues or the populations in the wild (although in my ideal universe that would be part of the concerns). It worries me because i like all caudate species just as they are

There´s more to it, though, and it has all to do with your question "why should we care about the survival of a species in captivity". I think we really should care. We should, because their future really does depend on us caring since we are in charge of that future. I worry because i don´t want caudates to go the same way as any other domestic species has. Their quality of life depends entirely on us and there´s more to it than decent housing and food.
I´m fully aware that it is imposible for a hobbyist to replicate natural selective processes or guarantee a large genetic variation in captive populations but the problem i have with this is the assumption that because we can´t do it properly then anything goes...I don´t see it as both extremes being the only options. I think some degree of effort on our parts can ensure that future captive populations will be healthy in the future. When i say i´d like captive populations to be coherent with wild populations i mean that i want them to be healthy, viable and diverse. I think trying to use nature´s standards for what works is a wise thing to do, even if we can´t get it entirely right, it will always be better than no effort at all.
If something works perfectly fine just as it is...why change it? And why allow it to change dramatically and uncontrollably, knowing that it will only impoverish their future?
On the subject of wether there is more to it than just having a pet, i have to say that for me there is, but it´s not a delussion of "working with the species" as we have discussed in the past, but purely a matter of aesthetic delight. I keep newts because just looking at them makes me happy, and what makes me happy is the thought of the beautiful naturally ocurring species in all its splendor. I really do like them just the way they are. There is a very real aesthetic pleassure in just observing these creatures.
I´ve used the words genetic integrity before, but i realize that it gives the wrong impression (after all in the wild genetic introgression of some form or another is quite common). I don´t use it solely in reference to unhybridized animals (which i don´t think wild hybridisation events can really be compared to a captive one), but also to their health and fitness, genetic and fenotipic.
The world certainly doesn´t stop turning, but it does become an impoverished version. One of the benefits of avoiding all the things that have been commented, hybridisation, lack of selective pressures, etc, is that you retain diversity and general fitness, if not forever (fat chance), at least for longer than otherwise. I´d personally like future generations to enjoy a planet that doesn´t suck...mind you, my hopes dwindle inexorably..
Edit: Chris put it a thousand times better than i did xD