If you don't trust your doctor, step one would be to find one that you do trust. If you don't trust any doctor, then you're going to have a difficult life should you encounter serious health problems.
And yes, you should stop drinking soda, diabetic or not. Nothing bad will come from not drinking it, but plenty of bad things can come from drinking it. Telling you this doesn't make either your doctor or me a "quack".
Except I didn't drink soda. I hadn't drank soda for like 6 years. The doctor didn't take ANY effort to determine what my actual habits were. He had an 8 minute appointment.. decided I must drink soda, and told me to stop.
And yes, you should stop drinking soda, diabetic or not. Nothing bad will come from not drinking it, but plenty of bad things can come from drinking it. Telling you this doesn't make either your doctor or me a "quack".