Counterpoint: progress is messy. In an ideal world, we'd shape society through rational democratic debates where everyone is discussing in good faith. Maybe we'll get there one day, but there are a lot of things in the way: poor education, economic hardship, inaccessible healthcare, wealth inequality, and biases deeply embedded in our culture. These factors not only make a lot of people unequipped to express nuance in their frustrations, they also don't exactly incentivize them to do so.

(And even if these issues are resolved, there are also the complexities of crowd mentalities that affect even very rational people. To overcome these complexities will take a mindfulness not really currently studied or practiced at scale.)

Throughout history, we've seen that change usually comes from very messy, ugly, forceful action. Polite discussion has its place, but when people are pushed to the limits, politeness is discarded and those who take action get what they fight for, polite or not. In those moments, enforcing "politeness" only works to preserve the status quo.

Politically correct mobs are a form of this - they are ugly and indiscriminate, but effective at shaping culture by stigmatizing ideas that have been used to justify harm. I'm not saying it's great - this is only a description of what is, not what ought to be. But people being mean or annoying online is as old as the internet, and is not limited to politically left-leaning people. It just happens that the mean left internet people are on the side of society's conscience, and luckily for now it's generally working for the greater good by correcting some big imbalances in American history.

Of course, the lack of accountability and balance makes this powerful hammer prone to swing wherever gravity carries it. It's dangerous, but to lash out against it is to lash out against the atmosphere for climate change - we need to address the root causes. We need to improve the livelihoods of everyone so they don't feel desperate and angry - this requires tackling hard economic and healthcare problems. We need to improve critical thinking so people can identify the truth - this requires solving difficult problems with our education system (which also tie into economics and healthcare). We need people to be more empathetic - this requires better urban planning, and all of the above. We need so many things and solve so many tough interconnected problems to get to the point where nuance and good-faith discussion rule society. Interestingly, these are all the problems that the mean left people are trying to fix. So it's possible to be on "their side" and not be in love with their techniques. It feels complicated, but isn't that what nuance is for?

Pushing back against the mob for being too uncivilized is trying to stop the swinging hammer, when it's probably best to just stay out of the way, and help finish building what the hammer is working on.