Mourinho said it was like playing in an "empty stadium" when the Premier League leaders beat QPR 2-1 on Saturday.
And the former Real Madrid coach, who also managed Chelsea between 2004 and 2007, was in no mood to take back his criticism of the lack of noise as his side prepare for a clash at Maribor in the UEFA Champions League on Wednesday.
"We are the team to get less support in home matches. When compared to my previous time I think it's getting worse," the Portuguese said.
"I don't question the passion and the love - I'm nobody to question that and I know clearly that is not true.
"I will always love them and respect them, but I don't know (why there is a lack of atmosphere)."
The London club are four points clear at the top of the Premier League after their derby victory over Harry Redknapp's side.
