Because many of those dogs are, in polite terms, screwed up. They need a good owner who knows what they're doing to help rehabilitate the dog, not a first time owner who might do things on trial-and-error. They just don't want the dog to end up back at the shelter, so they make sure they've given it the best chance possible by finding someone experienced.
Some shelters will rehome dogs to first-time owners, but often these dogs are ones which have come from a loving home with no behavioural issues. Most of the time though what I said above applies.
Never heard of shelters not adopting out to first time owners as a rule. Now, with breeds like Pit Bulls, YES I agree they should NOT be adopted out to first time owners. If you cannot afford a dog, DO NOT GET ONE.
It's as simple as that. Look at OTHER shelters and rescues. Dogs are not "affordable" items clothing or food.
I think you are a little mistaken about shelters as a whole.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.