Rather than fearing polarization, organizers should seek to understand how they can use it most effectively. This involves recognizing that, while collective action undertaken in pursuit of a good cause typically results in positive outcomes, not all protests have identical effects or produce equal benefits.
Central to harnessing the power of polarization is appreciating that, by its nature, it cuts both ways: the same actions that create positive polarization — drawing more active supporters into movements and convincing previously neutral or undecided observers to at least passively sympathize with the cause — will also have negative effects, turning off some people and firing up the opposition. The goal of movement participants is therefore to make sure that the beneficial results of their actions outweigh the counterproductive ones, and that they are shifting the overall spectrum of support in their favor.
So how, then, can movement participants predict how a given protest will polarize? And how can they work to improve their skills in designing effective actions?
History disagrees with you. The truth is that regular protests can be ignored, and voting may not always be very accessible (in non-democracies or because of voter suppression) or effective as a means to achieve change where you live (the US and similar countries because of first past the post voting systems). Direct action is absolutely a necessary and important tool for democracies to be functional whatsoever, and is in fact part of how we ensure good workplace conditions and good wages here in Norway (we have regular strikes as part of bargaining with businesses and the state). Hoping and waiting for things to improve is at best a recipe for nothing to happen.
It seems you think that disruptive protests need to be violent or damaging? Strikes are disruptive and harmless and very effective at changing things for the better.