Chaos theory is a part of physics that deals with complexity that Taleb would probably call complex.

Would he?

I don't think that Taleb would be a fan of wireless mouses.

More the worse for him. The markets have spoken and they like their wireless mice. Wirelessness, for all the added complexity - complexity which is much more complex than the problem it solves - seems to be carrying its weight, contra the Taleb quote.

Changes in tax law should not increase it's Kolmogorov complexity but reduce it. Low Kolmogorov complexity tax law would also be easier to understand in the more colloquial sense of 'complex'.

I doubt that. Here is where using a complex and not widely-understood theory can bite you: the shorter the code, the more computation you expect it to use to yield the specified results. The shortest possible code for anything reasonably complex will take huge amounts of computing power. (How much computation to simulate our universe up to the present moment using the minimal encoding of the Standard Model + initial conditions?) Any shorter version of the current tax code which has the same meaning will be much harder to understand than a version which redundantly spells out details and common cases for you. And if you change the actual meaning of the tax code, well, then you run into the public choice issues which made the meaning what it is now...

(It would be better to talk about logical depth and sophistication than simple uncomputable Kolmogorov complexity, but I believe even less that that is what Taleb meant.)

Washington politicians don't understand it. Even economics professors like our Hanson don't.

Why should they? Do we expect physicists to understand each and every area of physics? Specialization is one of the defining principles of modern societies.