I mean the aerial, off-stage double shine. Sure, he never gets punished for it, just as he would never get punished for a single off-stage shine. But it takes away his second jump, forcing him to up or side B back to the stage, which is slower than double jumping back.
However, if the second shine sends them lower, then I get it. More people should do it then, haha.
Also, sometimes I throw out a double-shine on get up or as my opponent approaches because their attack will clank with the first one, then the second hits. It's really hard to get right, but when it works, you feel like an absolute boss.