The impersonal meaning of "mne odnomu ne spravitsia" is sligtly different from the meaning of "mne ne spitsia" and is interpreted by many cultural studies specialists as a way of avoiding communicative responsibility for the action that will be/was performed. So "mne odnomu ne spravitsia" could be roughly translated as "I won't be able to manage it myself (but this is not my fault)" Conversely, by saying "ya odin ne spravlius" you take full responsibility for the outcome of the action.