Musar zu Divrej Hajamim II 13:20

Now if the reward of those who issue rebuke is so tremendous, it is difficult to comprehend Rabbi Akiva’s statement that he would be “surprised if there is anyone in this generation who knows how to issue rebuke.” Was Rabbi Akiva unaware of all the reward mentioned above? Why did he not rebuke the multitude for the sake of becoming a public benefactor? Moreover, as the outstanding personality of his generation was it not his responsibility to instruct the public? I believe the explanation is that Rabbi Akiva also realized the magnitude of the punishment for rebuking the multitude with impure motives and for shaming people in public. Thus Midrash Vayikra Rabbah (Parashas Behar, 33:5) comments on the verse, “And Yaravam did not regain his strength again in the days of Aviyahu and Hashem struck him” (II Divrei HaYamim 13:20): Rabbi Shmuel bar Nachmani said, “Do you think that Yeravam was stricken? In fact it was Aviyah who was stricken!” And why was he stricken? Rabbi Yochanan said, “Because he shamed [Israel] in public, as it is stated, ‘But you are a great multitude and with you are the two golden calves that Yeravam made for you, etc.’ (ibid. 13:8). If Scripture ascribes punishment to a king who only shamed a fellow king, how much more so a commoner who shames his fellow commoner!”