Kolmogorov complexity is relative to a choice of Universal Turing Machine. Because of the Invariance Theorem, the difference in complexity assigned by two Universal Turing Machines is bounded by a constant that depends on the choice of that pair. They can't disagree too much because one can always switch over to emulating the other. However, this amount of maximum disagreement can be arbitrarily large.
Given that, of what use is Kolmogorov complexity? I suppose if you have a sequence of bitstrings, then you can talk about the asymptotic growth of the complexity of these bitstrings, and you will know that this is independent of choice of UTM.
But I thought that Kolmogorov was supposed to be meaningful for individual finite strings. But every bitstring can be produced by an arbitrarily small program: imagine a language that functions just like Java but where an empty file produces the bitstring under consideration.
Doesn't this relativity make Kolmogorov complexity basically pointless? I must be mistaken, right?