Why do pretty girls like bad dudes?ladies only ?

Why do some of you girls like bad boys and I have heard that girls wanna change them well if you wanna change them why not just go for the good guy from the start why save the good guys for fallback?explain cus I notice girls use good guys for fallback so they don't have to be alone after getting heart broken by the bad guys that's kinda messed up think about how the good guys feel ladies am one of em