Hmm so it encourages you to spend hours at a time harvesting the same Pokemon over and over just to see if you can get a really good one with an ideal nature since I believe you can buy the services of a Fortune Teller to tailor the nature of Wild Pokemon encounters to the nature you want. So if you get good at catching Pokemon and consistently catch the same one over and over(which you'll need to do to do the mini-game in Safari Park for more Candy), then this promotes a bit of competitive play in Let's GO despite it being a streamlined version with no held items or abilities.
One wonders if this will apply to Kanto starters or Alolan variants(doubtful on the latter). In any case, it does raise a bit of an eyebrow for those competitive folk out there.