All Drs. are not bad.
I am very sorry to hear of your father's passing.
As a a DC, I get discouraged when I hear people lump all Chiropractors together after a bad experience. Albeit, your's is an extreme case and I can understand your anger, every Dr. may not have handled that situation the same. I am not saying your DC was wrong, as I don't know the specifics of the case, but please do not label all Chirproactors a bad.
I work in conjuction with MDs, DOs, DPMs and on a daily basis and maintain very good results. I am not a quack and tend to provide conventional muscle and joint moblization and ultimately rehab exercises (essential for overall stablization).
As with any type of shopping, it is important to feel comfortable with your Dr. and his/ her decisions. Ask questions... if your Dr. has difficulty answering, be weary.