Just to put things in perspective:
Tudor arrives at Juve after matchday 29. Juve has 52 points, 12 fewer than Inter at the top of the table.
At that moment, the standings read: Inter 64, Napoli 61, Atalanta 58, Bologna 53, Juve 52 (outside the Champions League spots), Lazio 51, Roma 49, Fiorentina 48, Milan 47. All within a 5-point range.
Just two matches earlier, we were in the Champions League zone, 3 points behind Atalanta, 5 ahead of Bologna, 2 ahead of Lazio, 7 ahead of Fiorentina, and 9 and 11 ahead of Roma and Milan respectively.
From a situation of relative calm, we plummeted down the table and were being chased closely by the others.
On top of the long-term injuries (Bremer and Cabal), as soon as Tudor arrived, Cambiaso got injured (on matchday 30 and again on 36), Gatti (on matchday 31, out for 6 games), Koopmeiners (on 33), Vlahovic (on 34), Kelly (on 35). Even Mbangula and Perin got injured — just for fun. Two players were sent off, Yildiz and Kalulu, both suspended for 2 matches, out of the 9 coached by Tudor.
Despite all this, Tudor managed to get 18 points and finish 4th.
In my opinion, this isn’t “achieving nothing” — it’s achieving an excellent result given the circumstances he faced.