Changing the protocol rules is identical to a relatively rare and discreet transition stages that any star undergoes in order to find a new balance point, when the old one no longer serves its accumulated mass. That's when the block size limit needs to be raised. The new limit needs to resonate with the whole ecosystem as it's supposed to represent the interests of the whole. It needs to preserve enough mass in the outer shell (users and validators), but leave enough space and entropy for internal competition (businesses and miners) to continue to produce goods with higher energy levels than before.