Those who question and challenge often do so to show their unhappiness or opposition

The questions are just an excuse. If you were to answer one question, they would come up with other excuses. If the Chasidim were strong in their belief that Lubavitch is good, then even a small amount of light would push away a lot of darkness. https://www.torahrecordings.com/rebbe/igroskodesh/011/008/3447