To be fair he has seen some success and that is why nobody really questions his methods. When you won UCL with this many different teams and you are ending up with bad results, that is not really that complicated at all, we should be considering this as normal because of his titles. He won so much with other teams, but let alone other teams, he won 2 leagues and 2 UCL titles with Real Madrid as well, which proves that he is a good manager at Real Madrid alone, let alone anything he has done beforehand.
Ancelotti is one of the greatest coaches of all time, his achievement as a manager speaks a lot about his experience because it takes an experienced coach to win a lot of titles in his gallery, and he won titles with almost all the teams he managed.
His performance as Madrid's coach is actually good because he has received a lot of praise in the last two seasons when he won trophies for the team especially the Champions League because the team struggles to win the title and he shows experience as a manager to make it happen for Real Madrid, but this is another season with difficulties which I am sure he will make things work out for Madrid with time.
This means that, if he is getting that kind of success, then people will not really be considering to judge him for not playing younger players, the fact that real is still getting younger players like Endrick and Arda makes no sense because they should realize that Ancelotti will not play them at all, even if they do fine, he is still not going to play them, unless there are injured players in those positions. So they should only hire experienced good players.
The nature and pattern of Madrid's style of play do not favor young players, because they only believe so much in already-built players that has already made names for themselves so that they can keep making the team grow higher; unlike other teams that believe in young talented players.
Ancelotti is the coach that has started given these young players chance in the team, and if he succeed with them, he will change the team's narratives because the young players now rule football.