I think that makes complete sense for hold-to-maturity investments like bonds.
I don't think it makes much sense for common stocks where there is no maturity. It seems to me that the longer a common stock is held, the less relevant YOC becomes.
As an example, I own some stock that I bought back in the 90s and still hold. My YOC on that is around 50%. The current yield is 2.14%. (It is AFLAC.) What does that 50% YOC tell me? It is definitely unrelated to the return I am getting / have gotten. (i.e. I'm not making a 50% annual return from the dividend!). If I'm focused solely on income investing, there are other stocks with a higher current yield that would produce more income. Switching to a higher (current) yielding stock would lower my YOC but produce more income. I just don't understand how that 50% number is useful in any way.
Perhaps someone has an example of how the 50% is used and provides meaning.