I think it is an ego thing, but I wouldn't be too harsh on the OP. I think the whole karma/likes/followers thing is based on a basic human need for recognition and acceptance. People basically like to be liked.
For some reason I'm one of the few people who doesn't feel the need to have 1000 followers listening to what I ate for breakfast (or the HN/SO equivalent :)
The other possibility would be that he wants to improve the quality of his comments and/or be a more valuable contributor to this community.