The process of putting the CRISPR genes in a cell and making them target a given gene is trivially simple and undergraduates around the world are doing it every hour (if not more). The Broad group did a little more than that, but it's nothing compared to UC's group's pioneering effort, and amounts mostly to breaking a certain part of the functionality and doing some very standard tests.
The tool is extremely effective, as you say, and was primarily "designed" via natural selection. The researchers (1) discovered it, teased out its mechanism of action, and its programmability, and (2) did standard molecular bio techniques to show that it works across several oragnisms.
This ruling is based on the fact that the original inventors didn't throw the genes into cells, publish, and (most importantly) apply for patents before the Broad group did. Whether it would work in those other cells was a crapshoot and doesn't represent any significant creative work, and a minor work of science. The importance is the result - we know it works in those cells.
Source: I also work in this field. This ruling is absurd.