It's almost certainly just the turf. I mean, that old stuff had regular ground balls skipping all the way to the wall with regularity. Olerud also played way off 1st if I remember right, so it's possible that affected his numbers too.
It likely has to do with the turf. That old stuff was basically carpet, and lightning quick. Alomar was magical at 2nd. If you remember Orlando Hudson (who was also excellent defensively), add a step of range to him and you probably get Robbie.
Probably too steep to be worth it for us, but there's a TON of value in getting 3 years of Snell. Maybe if they gave us Kiermaier instead of Margot it would help a little.