I'm sorry, but you have your science backwards. You don't dismiss evidence because it doesn't fit your current hypothesis.
Most significantly though, you grossly misunderstand statistics/surveys if you think it's possible to extract definitive physiological truths out of a subjective "how do you feel about remembering X?" survey.
For what it's worth anecdotally, I also can access memories from when I was 3-4 years old, and I can easily prove they're not fabricated memories because the memories in particular were not retold, and in some cases took some effort to actually confirm when I was the only one remembering them (even parents forgot).
Usually the memories are misc. trivia -- e.g. the design of the wallpaper of a house I only lived in until I was 4, a certain set of kids' cups I only used until I was 6, etc. There is no way these are false memories, because nobody told such things to me. I also remember some of my thoughts as a very young child, which is interesting, because they're very different from adult thoughts (though obviously I can't really "confirm" this in the same way I can physical memories).
Anyone saying childhood amnesia occurs completely is completely misguided. Of course, I have "childhood amnesia" like everyone else in the sense that most of those memories I haven't accessed in a long time, and can't recall them instantly at will. But they're still there, and I can access them with meditation if I want.