Disclaimer: I'm glad Jackie Robinson Day exists. Robinson was an incredibly important figure in the history of baseball, and an important figure in the history of the culture, and it's worth remembering that. He represents baseball at its worst, structurally, and its best, individually. Opinion: I hate that every player wears No. 42 with no name on the back of his jersey on Jackie Robinson Day.
Baseball is my favorite sport, but it's also the sport best tuned for casual viewing. There are 162 games a year, they're all on TV, and it's very relaxing—at least during the early innings—to maybe get a little work done while glancing back and forth at the screen. This is made marginally more difficult when the players have no identifiers on their jersey, particularly when the other team's at the plate.
I realize this isn't very important—but neither is the specific mechanism of celebrating Jackie Robinson on Jackie Robinson day. Personally, I've always been for not retiring the number across baseball, so that specific players—almost certainly well-respected clubhouse leaders on every franchise, given the reverence associated with the number—could wear it as a more personal tribute year-round.