Being a picky eater is not a favored survival trait.
Historically many survival foods, until recently they weren't generally considered special 'survival' food, more like what was left to eat after a long voyage or trip, were bland. Often barely eatable. Sometimes by design.
Hard tack, lifeboat crackers, military survival rations, are pretty far below normal fare for flavor and texture. This discouraged binging and helped conserve them for when you were really hungry.
I maintain a good supply of tuna, corned beef, Spam as both turkey and ham, salmon, kippered fish, and I know I'm forgetting one or more others but you get the idea. IMHO they are all good.
It is interesting that we refer to them as dog food. Many of the canned dog and cat foods are essentially what goes into products intended for humans. Many brands come off the same lines in the packing plants and go into identical cans. The difference being the label.
It also has to be noted that out ancestors simply loved canned meats, and canned foods in general. Sometimes depending on it before standards and technology justified their faith. The Franklin expedition of 1845, attempting to find the NW passage, heaped lead poisoning from improperly soldered can onto suffering brought by scurvy, extreme cold, and ultimately starvation. The canned foods were quite the innovation and even though the lead hurt them the crews survived for longer than they might without them.
A grand but tragic story of endurance. Read more:
http://en.wikipedia.org/wiki/Franklin%27s_lost_expedition
Of course it wasn't just poor technology that caused problems. Before the Pure Food and Drug Act of 1906 food handling and industrial canning operation had few standards and industry did pretty much as it pleased. During the Spanish-American (1898) war far more soldiers died of food poisoning than enemy action.
Anyone interested in food standards without government regulations might read "The Jungle" by Upton Sinclare. Free at:
http://www.gutenberg.org/etext/140Also available at any decent bookstore or library.
Some of out changing attitudes toward canned food has been the availability of refrigeration. If you wanted meat before canning was developed you dried and/or salted it. Even then moisture and heat would cause it to mold. Settlers and armies often resorting to transporting meat on-the-hoof. Ships often left port with live cows and pigs, complete with feed and provisions for manure removal.
Canning meant you could store food for years. Last I looked most of the meat packing companies say that as long as the cans are intact and not bloated their meat products don't have a expiration date. The date stamped on the can is usually a 'best if served by' date. The meat remains safe to eat long after that. Flavor and nutrition might suffer, particularly if the can is stored in the heat, but I have eaten ten year old corned beef and found it to be only slightly lacking in flavor. Other canned foods might not last as long and typically take on a tinny taste.
IMHO references to canned meats as dog food is primarily a commentary on the changing role and treatment of domestic animals. Working dogs would be fed, Inuits and shepherds typically set aside dedicated meals for their animals, but it is only fairly recently that most domestic animals got much more than scraps from the table. Dogs and cats were expected to glean food from the trash or hunt to make up up the difference.
The disdain for canned food is primarily a result of both man moving up and becoming jaded in our tastes. This is entirely understandable as we have prospered, fresh food is made easily available, and we increasingly treat domestic animals as pets and children instead of working animals.
Canned meat remains a mainstay for long term storage. Things get rough and that can of Spam you turned you nose up at might start looking good. In the mean time I kind of like a little corned beef or Spam sliced and browned in a skillet.