I agree with your points but the question is why some of the Congress leaders are always against Trinamool Congress? From their statements, it seems that Trinamool is the main enemy of Congress in this state.
My opinion is that State Congress wants the main opposition party status in this state. They do not want to be a part of any ruling party alliance. State Congress was converted into s sign board party in West Bengal. Recent anti government agitations has helped Congress to come in limelight and this credit goes to Trinamool Congress.