As more and more jobs are being created and more and more groups as well, there will be jobs that could potentially belong to more than one group. Think of it as categorizing the job. A job could fall into more than one category and is easier to find if a job that does xyz exists if it exists in more than one group. The only option we have right now is to clone the job into more than one group. The down side is that all the clones need to be modified when changes are needed.
This is where a shortcut to a job would come in very handy.