"Time management" may be ONE component of this game, but it is not the absolute objective. It may have been "manageable" with the beginning release of Sims 1-4, but with every add on, there are more and more objectives. If this is how YOU enjoy playing, more power to you... In your words: "This complaint keeps coming up and I just don't understand it."
Let me help you understand it... If it KEEPS COMING UP, it's a COMMON complaint, if it's a common complaint, just short of a general consensus, then maybe the developers should listen to the PAYING public and add time change management as an ADD ON... Then, "die hard" simmers, such as yourself, can keep playing against the clock, and others, like me and SO MANY others, can play at a more leisurely pace. Mkay? ;)