I believe Monica Lewinsky, largely because she had evidence (the blue dress) and Clinton admitted it. Gennifer Flowers had witnesses who collaborate her claim that she had a long term affair with Clinton. Paula Jones and Juanita Broderick’s claims were about as dubious as those of Cosby’s accusers.
I understand the desire to believe there’s truth in an accusation when a large number of people come forward claiming the same thing. The race to convict through media has to be avoided at all costs. The rush on Cosby accusations just happen to coincide with the release of a book by one of his accusers detailing her accusation and the accusations of others. There’s personal gain in this for some of these women and we ought not discount that.
Paula Jones got money from Clinton.