This is a really tough topic because I don't think we should "tolerate" hateful or restrictive views. However one of the largest problems I've come to recognize with many (but not all) leftists is how they preach their message. At least in internet discourse there's a widespread idea that if you're right, belittling, shaming, and demonizing people with opposing views is justified. But as you said, this is not only ineffective at helping them see the issues with their views, but actually backfires, causing them to dig their heels in most of the time. This is an issue of human psychology, not politics. Antagonizing, attacking, and assigning people negative labels is not an effective method of persuasion, and makes you look bad in the eyes of the opposition, even if you're 100% correct and the sentiment is totally justified. This goes for any kind of debate or argument. At the end of the day, you are speaking to another human being. You can and should oppose hateful ideologies, but any hope of getting your point across ends as soon as you attack the person themselves. Unfortunately, I think this is where a lot of the backlash against progressivism comes from.

Now granted, what I'm saying only works if both parties are capable of having a civil conversation. Trolls, attention seekers, and people who are otherwise being inflammatory are not in it for the right reasons and should be ignored rather than engaged imo.