It's really funny that you ask WHY someone need's a comment on their blog, THEN you ask for people to leave comments on yours and that "I do need a comment as well" So lets put stupidity here aside and ask ourselves a simple question. Why do YOU want a comment on your blog? To be famous? Will it make you feel cool? Or do you really know what comments may or may not do for your blog? I'm just curious to know if everyone online is as dumb as they are trying to sound.
It's good to know what people think of what you've posted. We all try to improve our posts and feedback is the best guage.
Well people leave comments when they like/hate your blog. Comments help you with your site activities which is good thing because it lets google know that your site is active which can help in the rankings.