go bad vs hit rock bottom

go bad

verb
  • Of foods and commodities, to spoil, rot, or otherwise become unusable due to age or storage conditions. 

  • Of a person or entity, to cease to be reputable and instead become delinquent, criminal, immoral, corrupt or poorly behaved. 

  • Of a geographic area, to become unsafe. 

hit rock bottom

How often have the words go bad and hit rock bottom occurred in a corpus of books? (source: Google Ngram Viewer )