Not produced any outstanding infielders since Betts? What’s the criteria here?
The reality is they’ve actually produced several infielders who have been solid to above defenders since Betts. Many were traded away, including Javier Guerra, Santiago Espinal and Yoan Moncada (who scores well on many defensive metrics, surprisingly.)
There were probably several other talented defenders whose offensive abilities kept them from advancing as well (CJ Chatham?)
It seems presumptuous to say they don’t teach defense simply because Devers and Casas aren’t good at it…