The 'problem' is that this tip has been posted a lot on HN/Reddit. It becomes annoying for some people to keep reading about a "git feature you're not using yet". That said, the feature isn't well-known for everyone and it is very useful, so you can only expect negative as well as positive comments.
I've been a HN user for 701 days (as of today). This is the first time I've seen this topic here.. Sorry not all of us are on HN 24/7. This is new to me, and I appreciate it being posted, because guess what? I've never known of git add -p. Now I do. But wait, what if the person who posted this did indeed see something similar posted here last year and never posted it? Great, now I won't ever have known this great feature.
Like stated before. Don't like the content? Don't upvote it. Move on. The complaining in every thread about these things are more annoying than seeing the same thing posted again after a month or two.
