Kind of both. Some people spend so much time on games they forget or never learn good social skills. And those people who aren't very social kind of find gaming as a way to communicate with others that share their interest.
I'm the ladder. I'm not really a social person, and so gaming, drawing, and computers are a way for me to enjoy myself. In fact, I have come to really love being alone. I don't have to conform to the rules of society if I'm in my own room. I can lie down on my bed, legs spread open, and as long as nobody walks in, nobody cares.
And that is a bit of take on the life of what the Japanese call a hikikomori. A person who shuts themselves in. I have never heard something that described me better.