It is perfectly fine to be super-nice as often as possible. But, the culture is "do not offend" dominate and almost void of "do not take offense".
This imbalance of cultural enforcement is likely a driving factor behind the younger generations view on enforcing standards of political correctness, social justice, etc. If you are offended then you are in the right, always, and without question.
Events where people get offended end up being reported online or in the media. Events where no one gets offended get no coverage, though that mind set is also very common. Additionally, extreme examples of "offensive behavior" are used by poth sides for political propaganda.
Take that with a grain of salt, there's plenty of stuff in the Bible that suggests overlooking offenses (things like Proverbs 19:11) and obviously forgiveness is part of it. But I'm not sure "take no offense" is quite the main component of that creed.
There's nothing puzzling about this. Most people who practice any religion with written principles almost entirely ignore almost all of those principles. The official principles of a religion don't really have anything to do with why people affiliate to one or another.