I have only been in one or two MLB dugouts and to a handful of college ball parks. All of them are set up this way. As a coach, when I would sit in the dugout, I would always be behind the netting that was there. Two summers ago (IIRC), a Hitters coach was hit while in the bench at the Rock. I think he passed away. Those dugouts are very, very close. Mike -- I would suggest full netting in front of the dugouts, please.
My oldest daughter hit a line drive back up the middle and hit a girl in the head playing High School fastpitch softball. The pitcher ended up in the ICU, but ended up OK fortunately. She was not wearing a mask. A few weeks later, she ripped a line drive towards the third base coach which hit his hand -- which was in front of his sternum. After five minutes, he was ok -- probably from the shock.
Three years later, we saw the same thing. Same high school team -- different hitter. No mask on the pitcher.
My three daughters always wore face masks on the infield. One was a PO, the other two were on the left hand side of the infield. There are some in the softball world who poo poo the notion. After seeing one girl getting hauled off to the hospital and another being taken by her parents, I have become passionate about that.
However, these are grown men. They can "make their own decisions," I guess. Mandating that they sit below the netting will not work. Putting netting all the way up in front of the railing will not solve the problem because players will still have their heads / arms near or above the netting. I would like to see it, though.
Finally, unless a 100MPH ball just stops after hitting the back wall, the entire dugout is at risk.
I equate this to hockey players being required to wear a helmet. It would be best if they work a full face cage, but they don't. They get hit in the mouth with the puck and, although rare, it is a result of their choice.