Whether to actually bail a person out is a decision usually left to friends or family who have access to the funds to bail the person out. Some family members become fed up with past criminal behavior and choose not to bail out their loved ones.
As far as whether a bail bond is necessary depends on how you view the best interests of the person. Certainly when it comes to developing a criminal defense, it is very beneficial to have the person out of jail. People who remain in custody tend to sign plea agreements in order to try to get out of jail, and this is not always in their best interest.
A criminal record can follow someone for a lifetime, so when making a decision about how to resolve the case, it is best that the person has taken the time to examine all possible outcomes and defenses. This is best done while out on bail.