Although the "GetNums" function would indeed make this simpler in-line, it simply moves the complexity to another routine. Combined, the two parts have nearly the same code.

That having been said, standardizing common functions like getnums() is a good practice. The article is probably best viewed as a general approach to reporting on "sparse data". Instead of hours or dates, consider regions, possible questionnaire responses, etc.

I've found that using in-memory tables and "building" results incrementally to be much clearer and less error-prone than highly complex joins, and with very acceptable performance (consider the use case...) I've seen many cases where the added developer time in debugging and maintaining far exceeds the additional performance time over the life of the application.