It’s a clear signal the paper is gonna be hard to read. It takes a ton of work to compress complex ideas down to 8 pages for a conference paper. But that work makes it easier to understand. This paper did not do that work. In fact it seems they did the opposite: try to write a LONG paper as if that shows how much originality they have.
While it's less than ideal it's also a very useful (and pretty accurate) heuristic to weed out papers in an area where it is impossible to read all (or even most) of them
