The CCRS handbook covers the basics pretty well - as to the importance of the structure. Technical skills are always changing. Leadership skills are important for PMs and PgMs to ensure that the best is got out of all participating members. Strategic skills are important for considering non-immediate consequences and opportunities.
If your question is one level deeper - why that particular structure - I do not have visibility into the research and the process that led to that decision. But, as with anything coming out from the PMI, I trust it would have been exhaustive. Saving Changes...
I think it is to prevent PMs from just developing one dimension of their capabilities. A well rounded PM needs to develop across all three legs to remain effective. As per earlier posts of mine, I'd have liked them to have required a certain number of PDUs for the Giving Back category, but failing that, at least they have balanced out the learning category...
I think it is because PMs more well balanced in their skill sets.
What I find troubling is with this whole process is that it is really easy to find technical training and leadership training, but when you go to find training that has Strategic components they are in very short supply. Even at the Global Congress it was difficult to get PDUs in that area.
I worked on our local chapter's Professional Development Day and really tried to push for getting at least two seminars on Strategic topics, which was hard for a variety of reasons like lack of choice or the speakers wanted outrageous amounts of money and then when we finally had two under contract, one she cancelled at the last minute, so we filled the spot with whatever we could find and that caused a lot of poor reviews for the event because that's why people registered for the event.
