Incomprehensible LaTeX soup IMO. What value does this paper afford one of us "hackers"? It would take me weeks to digest this to only find it was a bunch of bullshit talking in circles over exceptionally pedantic topics that have no real world applications.
For many researchers MCMC is described in very specific terms very differently in many places. This paper offers a single view of how to understand the idea and how you can use it to derive specializations for your field. Of course if you have no interest in mathematics, just move on. Nothing about being a good hacker means being abrupt and unwilling to dive deep in the necessary tools for a job. I for one am glad to see a paper like this and know I can start from here to build my own sampler for a complex system for which there is otherwise no software to efficiently sample. The hacker spirit is curious and open minded, but moves fast. If it's not a tool for you that doesn't mean it can't help thousands of others gain real insight into a difficult subject.
There is lots of specialized knowledge posted on HN. As a factual matter, MCMC is definitely not without real-world applications.