I agree there is some philosophical greyness here. But let me try again.

Let's say we are adversaries. I am going to choose a data set which I claim is simple, and you are going to try to prove me wrong by picking a weird Turing machine which assigns the data a low probability. I generate my data by taking T samples from a sine wave. You pick some strange Turing machine which is designed to be unable to produce sine waves. But regardless of the choice you make, I can always just crank up T to a high enough value so that the compression rate of the data set is arbitrarily close to 100%, proving its simplicity.