Maradona was hired due to massive, and i mean, massive, popular demand, the AFA didn't want to hire him, the journalists thought it was stupid, but if they hired anyone else as soon as they failed to win one game the situation would quickly become untenable, so they caved. He was massively criticized by those few journos with enough balls/nothing to live for
Even after the WC argentinians still far and wide wanted him to continue, Batista(his successor) was pretty much persona non grata in Argentina even leading up to the home Copa America a year later, and when they went out to Uruguay(and the 2011 failure had a lot to do with Messi - first Batista tried to accomodate him by playing the team he wanted, didn't work at all and Bolivia and Colombia effectively erased him, so Batista went with the team he wanted to play for the final must win game against Costa Rica, won convincingly and repeated it against Uruguay, where Messi was a ghost and blew the chance to win the game. He was under colossal pressure and caved completely)
Btw, this is the team argentina should have played in SA: GK- Zabaleta, Samuel, Demichelis, Zanetti- Mascherano, Cambiasso- Di Maria, Messi, Lavezzi- Milito. This is if not the most talented team in the tournament, then at least a close second. It's also complete, and with good depth almost everywhere, but especially in attack. Alas
Also, the idea that Martino and Valverde were poor managers is insane and denotes a complete lack of understanding of football. Martino did good, the team just wasn't as good as people thought anymore, and competed against Atletico and Real Madrid. Valverde, well, we've actually seen exactly how good of a job he did just by looking at how bad his successors were in comparison
