not really, my claim is that if random data reproduces the trend (e.g. experts undepredict, layment overpredict skill), then it might actually make the argument

not really, my claim is that if random data reproduces the trend (e.g. experts undepredict, layment overpredict skill), then it might actually make the argument stronger than the traditional explanation. The traditional explanation is that there is some secret bias where idiots think they are smart and geniuses think they are dumb. A stronger explanation supported by the random data example is "people can't assess their skill at all". The expert / laymen tails appear only because they are at the high/low end of the distribution and there isn't any higher/lower to go, so the errors go towards the middle. So there isn't a bias its just that the ability to understand skill is a skill itself, so the random errors look like a bias.