Within a functioning dictatorship, softliners can play a role by helping to moderate the dictatorship and by making it more palatable to the people who live in it. When there is a hardline and a softline faction under the dictator, the softliners can push for more lenient policies and can, thereby, make the dictatorship not seem so bad. If, by contrast, there are no softliners, the dictatorship will be harsher and may be more susceptible to being overthrown by dissatisfied citizens.
Softliners are also a major part of possible transitions from dictatorship to democracy. During the dictatorship, they can push for more liberalization. If, then, something happens and the dictatorship starts to fall, they can provide a "soft landing." Since they have already lightened the dictatorship, and because they are somewhat trusted by the people, they can serve as a step between the dictatorship and a truly democratic system that might eventually evolve.