Never played pikmin 3, but I had a funny experience with the day limit in pikmin 1. You have way more than enough time to complete the game in the day limit, even if you play very suboptimally.
Despite that, in my initial playthrough I still hated it for all the reasons you listed. Theoretically, I could see how a day-limit could be good for the game. Adding tension and the like. But on that first playthrough when I had no idea how much time is worth, I always felt the need to rush. As it turned out, I could have easily taken a few days to just explore or strategize. But there's no way to know that at the start. Maybe it could work better if the game could communicate somehow if you're ahead of schedule or something.