Just as cellulose acetate has the vinegar effect, cellulose nitrate has the "nitrate" effect and for the same reason. Cellulose nitrate is (IIRC) guncotton, a close analog of nitroglycerine, but more stable.
And finally, the film in a can is in an enclosed space. A stack of cellulose nitrate films can explode if one begins to burn or is overheated. After all, they are in an enclosed space, the can, and are in an oxygen poor environment.
Nitrocellulose was designed to burn in the absence of oxygen and to explode in confined spaces. That is the nature of this beast.
The generic chemical family is "nitroglycerine", "nitrocellulose" and "tri-nitro toluene". The first is a liquid at room temperature, the second and third are solids. All are similar in properties being flammable and explosive and somewhat unstable (to say the least).
So, even if I could get a stable film base, I would not want to have it around or store it.
Not advocating the return by any means, but it does have the best record of flexible film bases, ever.