If you don’t know what you are doing with nofollow, noindex and robots.txt you can royally mess* things up (face to face I would use a stronger term). Even if you do know what you are doing, you can still mess things up.
I benefit from being a top commenter on a number of blogs simply because I am consistently active on those sites, and I have gained the benefit without changing my commenting habits.
Some of my blogging friends are aware of the problems, but have opted to use such a plugin anyway – I fully respect that decision, but many make that decision “blindly” without being aware of the possible consequences.
Whilst working on an elevator speech suitable for non-technical potential seed investors, I was chucking loads of word combinations around and came up with two very unique definitions that describe what I am trying to achieve with my startup projects (I am looking for a CTO partner).