Soldato
Would be an awful idea. Imagine if you had a player who was awful, no one wanted to play with him but you had to play him every game of the season. Thats essentially what you are suggesting with the manager being unable to be replaced. There is huge money at stake and the manager is arguably the most important person on the front line for the club.
Its not fair though is it. Teams go through good and bad patches of form. Would you complain if you played Chelsea early in the season when they were flying high, didn't play them during this downturn for them but then had to play them again near the end of the season if their form returns?
Forcing a club to stick with a manager that has lost the dressing room or appoint a temporary interim from within the club would have almost 0 benefits and so many issues.
I don't reckon it's that bad, just like players the manager could be side-lined if he was causing a rift - the club then would have to rely on it's coaches for interim management?
It would just put more importance on understanding the managers/coaches you hire and ensuring they are a good fit with the club and squad.