Why does it say "v'Chol Ish Yisrael"? It said that "Kol Ziknei Yisrael" (verse 4) approved of Achitofel's counsel!
Ralbag: The Zekenim did not approve of Chushai's counsel. Abarvenel - they were drawn after Achitofel. The entire nation loved David 1 .
David was told that Lev Yisrael followed Avshalom (15:13)! Here we discuss the people with Avshalom, who heard the counsels. Perhaps these were people of Yerushalayim, who knew that David does hear people's claims (and even dirties his hands with blood, Shefir (the outer skin of an aborted fetus) and Shilya (fetal sac), in order to permit women to their husbands - Brachos 4a)! They pretended to follow Avshalom, either due to fear of him, or to gain his trust in order to help influence him, or be able to inform David of his plans. (PF)
Was Achitofel's counsel good?