Not sure how I feel about it, even though we hate referee judgment (I get it) if anything there should at least be intentional vs unintentional PI. DBs in the pros are fast enough to make up the time to clip a WR that has them beat at times and ruin a big play. Last thing I really want to see is a muddied up game because of obvious intent to stop a big play.
But no doubt it would be great for some of those 50/50 type calls to be limited to 15 yds as opposed to the refs simply making the catches for the offense with a flag.