I also think so because nowadays I hardly get backlink from "Blog comment" so from now onward I am just doing "dofollow blog comment" and in that chances of approval are very low.
Comments are great way to show how well you are writing interactive contents. Google loves it. If you get more comments often, google increases crawl rate in your site.
Blog comments are fine, if done on related sites, and are done naturally. I believe Google is looking out for what they consider to be blog comment abuse. I advise that you avoid people or automated programs that submit tens of thousands of blog comments for you in a few days time, and instead that you do a few manual comments on better quality (and more relevant) sites. Blog comments should be part of a comprehensive, well-managed SEO campaign in my opinion.
Most blogs have nofollow option on comments. It think it's waiste of time, unless you have a lot to say and know how to attract attention.
Some of them are good. It is not just the backlinks you are looking for but readers might be interested in your website if you contribute something useful.
Blog commenting is good because in provides additional exposure to the site you are promoting...& it also has a bad site because most blogs is moderated.....
There is absolutely nothing wrong with blog commenting, they do help in some-way. Just comment on relevant things to your niche and not try and spam them!
As far as my observation goes, dofollow links do help a lot, specially since do-follow blog commenting is the only way of getting your link up on a High PR page free of cost. Also, when a link is added well within the comment section and considering the comment is long and relevant enough, that particular link is as good as a natural baited link.
Bog commenting is one of the easy way to improve your PR and SERP. However, you need to check whether the blog is dofolow or not, nofollow will not give you PR juice, only dofollow will provide you PR juice
I love it as I have alot of my back link from blog comment but you hate to find dofollow blog comment will help you Thanks