A group that has the numbers, with mild views that can dilute your message with reasonable doubt, challenge certain aspects of your extreme yet be broadly acceptable to a much wider audience including those tending towards your side – that's poision for an extremist.
Therefore, their solution to that is tribalism, polarization, and shaming for any hint of non-compliance with the extreme's dogma.
End result is that the vast majority of moderate people do not participate in debates on sensitive topics, leaving the field open for polarizing demagoguery. All that's left is to make more topics sensitive to get an advantage there too, and that's progressing very well too.