My working assumption about shifts in baseball has been that they work so often that when they don't, it sticks in our minds. I also kind of figured pitchers who get burned by a shift now and again tend to see it the same way.
It's a similar dynamic to errors. They are a rare thing these days. We're on pace for 2,730 errors this season, which would be a record low, and the league-level fielding percentage (.985) is in a race with 2013 as the best ever. So when a player does commit a miscue, especially at a key juncture of a ballgame, we remember it.