Really the most frustrating part of PM. I have never had a PM that understood "we could implement features faster if we took a little time to go back and tighten up the code". Instead it's just a constant stream of one feature after the next with whatever got written down the first time by a fresh college grad being the golden solution.
It's particularly frustrating because PM tend to measure success by the number of features produced. That alone incentivizes a fair number of devs to just pump out shit without thinking about what they are producing.