Losing 9 games from 21 matches played by Roma can be said to be not good enough. Its normal, if many people blame Roma's performance is not so good under Mourinho. The reason is, Roma expects more from Mou to bring back Roma as top 3 Serie-A clubs. we know, after Il Capitano Totti retired, Roma look like losing his life. Indeed, it is not easy for Mourinho to develop players like when he was at Madrid. However, as a coach who has often won trophies, he should have been able to make changes for Roma, even though they didn't win, at least finish in 4th position.
The same thing I think that Mourinho did not take Roma to a good enough even to finish 4th only very difficult points far enough while those above him continued to add points much better than Roma, but indeed the quality of Roma's players was not so optimal so Mourinho can be said not yet capable enough to develop his players.
I doubt Mourinho can bring Roma to finish in the top 4 of the Italian league this is quite difficult for him and against big teams he is not able to.
I mean it is always assumed that Mourinho will get more out of a team, because of his defensive style known, he always has this expectations where he would have very little loss and a very good points per game averages. However we have seen him not be great for a long time, and that is what we are seeing in Roma as well.
If you ask me, Mourinho is done, he is not going to be managing any big teams ever again and he is not going to get too much success at the top level ever again. That is of course what I believe, maybe he will prove me wrong and he will win UCL with another team one day but he is not going to be doing that any time soon.