It takes a very special person, a very special pet, and a very special connection between the two to make a rescue work for both the pet and human involved. It also takes time, love, strength, and devotion to the cause to carry it through and to give it your all.
It's a terrible thing what some so-called humans do to these poor, defenseless furry babies. Then the shelters end up trying to fix these poor, broken pets and try to train them time and again to believe that another so-called human will not do the same, so they get placed from one wrong place after another because the special connection needed in the first place just wasn't there.
Before adopting out a pet to a home, educating the adoptee is a necessary part of the process, or it just will not work and might further damage the pet.
It is a very difficult job indeed to work at a shelter. It would kill me, too, to see some of the terrible, awful things firsthand that so-called humans can do to destroy a defenseless, loving pet.