Those guys though are not Willi and Harold or Niko Goodrum. Niko was the poster child, indifferent defense at 7 positions, and a switch hitter who couldn't hit at all from the left side. Good players who can play well at several spots are nice to have, but I don't remember the Tigers having any since Tony Phillips and Skeeter Barnes. Lots of guys play 1B/OF, or SS/2B, that's very common.
Nobody is saying that versatility is bad. A couple of people though are saying that "chess pieces" should not be a development objective. The objective is every day players. Maybe they play 140 games now instead of 160, but they are every day players.