You overshare personal stuff
People get irritated with self-centered personalities who over talk about their lives. Very few people are interested in viewing your pictures and knowing about your daily routine. The majority of people may not be comfortable with this habit of oversharing.
Your negative thoughts
Showing only anger, dislike or discomfort makes the majority of people disinterested in contacting you. According to researches, most people may cut off negative people in order to enhance the quality of their lives. Negative people affect others’ lives directly and indirectly.
Different ideologies and beliefs
Some people are radical and unable to tolerate differences or to accept others. Sharing your own opinion about critical issues like religion or politics may lead to debates. People may not like to listen to different points of view, thus they end up unfriending you
Developing a stalking habit
Hitting the like button or commenting on every shared post gives an impression that you are a stalker. Most people are uncomfortable with being closely watched, thus they tend to protect their privacy by unfriending the stalker.
Game activities and invitations
Not all Facebook users are interested in playing games. This category of people may feel frustrated and irritated with the constant invitations and requests they get to join games. In order to get rid of the overwhelming notifications, they may cut off the sender.
Breaking up with someone
Most relationship experts advise people to delete their exes and crushes to quickly move on. Accordingly, some people get deleted or blocked by their exes. In addition, being a friend of someone who passed through a recent break up could lead to the same action from their former partner.
People may delete their crush or close friends on Facebook in order to get attention or a certain reaction out of them. These people may initiate an argument by this silent activity instead of talking directly to the person. (See What happens when you Unfollow someone on Facebook?)
There is no contact in real life
On Facebook, people establish connections with former school or work mates who are no longer part of their real lives. In order to attain a level of privacy, people tend to filter their friend list every now and then so as to keep only those who they deal with in real life.
Younger users do not like friending parents
Teenagers and younger Facebook users do not feel comfortable adding their parents or older relatives. They may feel watched or criticized, so they delete them in order to maintain their privacy and freedom.
The bragging attitude
Always being happy and satisfied sounds unreal to the majority of people. Showing constant updates about your happy life may make people feel jealous. To remain satisfied with their lives, people with exaggerating posts may be cut off.
Having no Facebook activity
Sharing nothing on Facebook gives the impression that you no longer use this account or you quit Facebook. In both cases, people will delete you since there is no actual communication between you both. (See What happens when you unfollow someone on Instagram)
Why you are suddenly unfriended on Facebook?
What happens when someone unfriends you on Facebook? Here’s why you just got unfriended on Facebook