While that may be a reason, I strongly suspect the real reason is that engineers simply don't want to spend time estimating. In my experience most people think

While that may be a reason, I strongly suspect the real reason is that engineers simply don't want to spend time estimating. In my experience most people think breaking projects down into small chunks and estimating each chunk is terribly boring, they'd much rather have bigger and less defined chunks so they can start coding faster. I think thorough planning and estimations usually makes for both better and faster outcomes, but I'm unlikely to push for it simply because a full day of planning (or more) every two weeks is pretty damn boring. Doing some light high-level planning and diving into things is less efficient, but way more fun even if you end up having to backtrack more etc.