We live in a culture where cutting off friends is seen as an acceptable way to end a friendship. We think it's normal and that there's no need to talk a problem out because "you should know what you did wrong."
Unfortunately, some people aren't as attentive to specific situations as you may be and thus do not actually know what they did wrong. And even if they did know, you should want to/be able to talk to said person about it instead of giving them the cold shoulder and pretending they do not exist. We are adults now. This is the real world. And though some people think having to tell someone when they did something wrong is babysitting, I believe it's more childish to not talk about it at all.
It's honestly harder to talk about your feelings and butt heads with someone than it is to cut a person off completely, and I know sometimes this is the very reason people don't even bother to try... But I don't understand how you can leave a friendship without at least trying to understand what the other person's intentions were. How do you leave something and know only half the story?
I hate unfinished things. I despise having words left unsaid and I absolutely cannot stand having people not understand me. Can you?
When you have an issue with a friend, your first instinct should not be to stop talking to them, it should be to confront them about it. After all, no one can fix something they didn't know was broken. Throughout your talk, be mindful. Listen to understand what they're saying, not to respond with your point of view. Nothing gets done this way and it's the reason so many friendships end on bad terms. One person doesn't understand the other and vice versa.
In friendships, it's also okay to agree to disagree. You can be different in so many ways and still love and respect each other enough to remain friends. Your friends cannot possibly be replicas of you, and if they are, that's a bit boring. Don't get me wrong, I love me and having myself to talk to is essential but I wouldn't want to solely hang out with myself. Having a diverse set of friends with differing opinions and attitudes makes for interesting conversations and a variety of solutions to problems you may have. Don't be afraid to be friends with someone who's different than you, it could end up being the best thing for you.
When you have friends who are different than you are, you are going to argue. It's a given. But it is certainly not the end of the world, and you shouldn't treat it as such. Be sure to talk out your issues instead of cutting people off. It makes for awkward encounters and is overall a childish way to handle a situation. If you don't want to be friends with someone anymore, that's fine. Don't leave anything unsaid and make sure the person is clear where you stand.
You are never forced to be in anyone's life, but giving a reason for your disappearance is always courteous to the friendship that you once had with this person. Remember that they meant something to you at one point. Try not to make them feel otherwise.