For all the excuses for Ralf that are based on him not being a permanent appointment, do remember we've had a caretaker manager before, quite recently actually. He took over a side that was awful and achieved the "new manager bounce", then turned that bounce into a run of good form.
The evidence is that Ralf is out of his depth. No surprise given his achievements in the game are average and limited.
Not that I’m defending Rangnick, but the caretaker manager was a welcome relief in the players’ eyes from the experienced manager who was sacked and the players responded in kind. This time, they don’t give a shit.