Because product managers struggle to comprehensively understand value add and have instead replaced stating business goals and value add with bullying based micro managing tactics like counting lines of code and conflating other such arbitrary metrics related to code with having a 1:1 ratio of accomplishing the goal and do not respect the thought of troubleshooting, architecture design (unless you take another two days to turn it into a diagram presuming it needs to be consumed by some other party) and finding an elegant way to implement code to accomplish the goal as work because they can't see it, and they can't understand it because they are too busy collecting visual days to prove they are properly micromanaging you to take the time to learn the challenges inherent to the architecture and challenge at hand.

Does that help?