Like insomniasexx said, the username and all tags are presented as they give information as to why the post is in you feed; the one you follow is blue. If we hid the personal tag, it wouldn't be immediately obvious why that post was in your feed if you only followed the personal tag. One option would only to have the personal tag appear if you follow it, however, it seems a bit odd. Another reason for presenting it (and this one became much more apparent to me as I tested), is accessibility to the personal tag page. I found myself clicking the personal tag as a quick way to see the user's contribution to that tag. In my limited experience with it, the personal tag becomes a window to content discovery. That being said, if there is a way to aesthetically improve this without compromising the functionality, I am all for it.
What if you condensed into #tag.user and highlighted "#tag" when you follow the tag and "#tag.user" when you follow the personal tag? And then have a similar system for hyperlinking - clicking "tag" sends you to the tag, clicking the "user" in "#tag.user" sends you to the personal tag, and clicking the "user" in the author field sends you to their user page. Disclaimer - this might be really difficult to code, I don't know. I dabble in web design, but nothing this complex.