I know at least two people have mentioned that they tried to leave a comment and weren't able to because the protocol for leaving it is not all that intuitive. Though I'm grateful for the Blogger software, which overall is very well-designed, especially considering the price (free), I have to agree with the critique for comments.
At the bottom of each post, you see a envelope icon. Kind of looks like where you'd leave a comment doesn't it? Especially given the context that it's at the bottom of the post. It's not the place. That's where you email the link to the post to your friend. The word "comments" is down there too, but there is no icon to click on. By now, some readers newer to blogs have already given up on leaving a comment. Now you blog savvy folks would have no problem, but let's not come down with a case of expert-itis. Keep in mind that at one time all of us were figuring out how this stuff worked.
Turns out that you leave the comment by clicking on the word "comments" itself. The actual word is the link, though there is no underlining before you run your mouse over it to indicate that. So those of you who have tried to leave comments without success, give it another go. For those of you who haven't left any, go ahead and press the comment link. Say whatever is on your mind. Leave your mark. It'll do ya good.