For me it was the complexity of making gelatin dry plates. Between the noodle washing and cold flat stone, I decided that my collodion technique was far better than my (zero) gelatin experience. Collodion also permits me to intensify the negative in a couple of ways- I can leave it "soft" for modern silver gelatin paper printing, intensify "bullet-proof" with copper sulfate for salts or albumins, or iodine re-develop for VBD or c-types. I like those choices.
Gelatin glass plates are probably fleixible too - but they are the devil I don't know. And I apologize for not printing platinum. Your work is this area is just terrific and I look forward to learning this process in the next year.