We are all told to believe that yes, it is so. But is it really true? Now I'm not saying that you should go around starting fights and being in general nasty. Yet, I do believe that modern Western niceness has been taken to a very unhealthy degree. I remember how I was taught in my English class that "English people are always saying sorry." (Not that it's much different where I live). Is it really healthy? Should you apologise when you did nothing wrong? Should you always go out of you way to please others? I don't believe it.
Before you start talking about Christian morality, Eastern and Southern Europe are much more Christian than the West, the North and the Anglos and yet they aren't afraid to stand up for their rights. They aren't such pushovers. Imo, what is presented as "Christian" nowadays is just bourgeois (Anglo-) Protestant Victorian morals. There lies the root of the modern moral crusaders and virtue signalling. Bourgeois people often hate working class because they see them as "crude" (nowadays mostly accusing them of various "isms"), and constantly virtue signal in order to prove themselves superior.
Upper classes will virtue signal in public but in private life will just live like they always used to, btw. Their status isn't in danger so they don't really have to prove anything. Bourgeoisie, on the other hand, is constantly socially striving. Think Hyacinth from "Keeping Up Appearances." The latest trend by bourgeois youth is snitching on their own family being politically incorrect for social upcummies.
This is truly despicable behaviour and no other group outside of Anglo-Europeans is doing it. "Snitches are *itches who wear stitches", comes to mind. Unless someone of your family engages in really horrific/criminal stuff (like child s*x abuse, for instance) you don't snitch, period. Snitching on your own flesh and blood for making a politically incorrect joke is lower than low. Only someone totally devoid of all honour would do it.
Being bourgeois doesn't equal being honourable or Christian by any means. Don't be bourgeois. Don't be afraid to stand up for yourself. Don't apologise when you've done nothing wrong and you know it. It's even worse when it comes to politics. Conservatives always lose because they always want to keep moral high ground. They equal being right wing or trad with being bourgeois. The other side will fight dirty and stick by their own, no matter what, but conservatives will thought-police and disavow.
There was a (now defunct) Christian site which used to republish religious tracts from the times of the Reformation. One of them dealt with fighting your political enemies. It rightly pointed out that "turning the other cheek" was a command on how to behave in your private interactions and had nothing to do with political struggles. "In politics", the author wrote, "one answers words with words and steel with steel".
But even in private sphere, "turning the other cheek" simply means not starting a personal vendetta because of every little thing, it doesn't mean you should just allow yourself to be used and abused. Christian doesn't equal a doormat.
So is being nice a virtue? In general, there's nothing wrong with being nice.We all should strive being agreeable to people around us, as far as possible. Just don't take it too far and turn into pathological altruism.