The .22 LR is far more beneficial to a guy trying to survive than a larger center fire rifle. He can carry more ammunition to hunt small game with that is easier to deal with than one large animal on the ground.
That's not entirely true, it depends on your requirements and outlook. I understand the logic ( behind the 22LR as a survival choice ) and it has been oft repeated but here is where I take exception. In a survival situation you can hunt small game for sure, but you can't hunt big game with any certainty at all.
From a survival perspective I don't just want big game for food, I also want big game for skins, bones, sinew ... these things can become essential for items of shelter, clothing, tools as well as sustenance. If you are familiar with any of the classics on Bush survival in my country a big cal gun is going to offer more flexibility than a small cal in the long run. You'd be spending a long time hitting small game just trying to get one big sheet of skin or leather for shelter or clothing, sinew for rope etc and large bones for any number of tools and items.
A big animal can also serve as a vital source of water and hydration - drinking the blood of a large animal can save your life in desert regions - a small animal would not offer much in this way at all. You could be out there wasting a lot of precious time and energy trying to fill your quota of small game to get the things you need - things that could be gotten in a one stop shop with larger game.
Finally ... if you come up against an animal that threatens you of any decent size, then personally I would much rather put it away with a .303 or .308 on than the 22LR. There are certainly pro's and con's of both in a survival situation but for my taste the pro's are far greater with a bigger cal than not. I make these comments only in the spirit of healthy discussion and not some zombie SHTF fantasy context. I've studied my country and thought long and hard about the requirements of survival so thought I would share my reasoning on this matter.
Different environments may demand a different solution.