When a guy and a girl are friends, there can be different reasons that this happens such as feelings, having a hard time connecting or someone that just needs a friend.
Here are some reasons guys put girls only on the friend list and not anything more:
Unintentional
Some guys want to be friends because they meet someone that they think is amazing, but they do not want to be in a relationship. This is nothing against the girl, they just do not want to be tied down with her at that time.
Focusing
Guys might decide to have a girl just as a friend because they are focusing on their life and having a relationship is not the right time.
Talking
There are some girls that guys meet, and they like them pretty good, but they do not want to take it further than friendships. They find that some girls become too clingy and not every guy wants to leave the friend zone.
Type
When a guy chooses to keep a girl as just a friend, chances are he feels that she is not his type. This can make being friends awkward at time, especially if she feels more feelings than he does, but it is better to let her know right away.
Spark
Sometimes a guy will not feel a real connection with a girl that he is friends with. This does not mean that there is not an attraction, it just means that there is not a connection emotionally and physically. Whatever the reason, when this happens, guys just want to stay in the friend zone.
Make Things Hard
When you have a good friend, guys sometimes do not want to mess that up by being in a relationship. Some girls become attached and this can make things a little complicated.
Attitude
When a girl spends time with a guy, he might decide he does not like how she acts or her attitude. When this happens, it is best to just be friends and not to date her.
Friend Zone
Some girls think that a friend zone is just an excuse for guys to not have to tell a girl what they really feel. When you have a friend, the best romantic relationship can come from this type of relationship. Men will use this as an excuse not to date because they do not want to be romantically involved at the moment.
Qualities
When a guy is attracted to a girl, he looks for more than looks to see if he wants to be with her. Sometimes the attraction can be sexual or sometimes it can be deeper. Regardless of what the reason is, when a guy just wants to be friends, chances are he is not with someone that has the qualities he is looking for.