Independent thinking is not on par with the Borg theology.
Independent thinking leads to cognitive dissonance.
Cognitive dissonance leads to doubt.
Doubt leads to apostasy.
The Borg has to have that element of thinking done for its victims.
Without the thinking done for them,,,they lose their power and control.
Then comes loss of members.,ultimately loss of $$$$
The higher-ups depend on that $$$ to sustain their lifestyle and control .