The tagline system is awful simply because people insist on using tags that do not apply to the area, most likely to scalp votes.

Communities should help this although that would require moderators which I am not sure is the answer.

Photography might be a bit easier to alter since it is possible to scan through the posts to see if there are any images in it. Of course, one could simply post travel pics like you alluded to and end up with the same thing.

I share your frustration when I go into the steem tagline looking for updates about steem pricing, movement, or articles about the token. Instead, it seems to be a catchall for anything posted on Steemit.

I wish I had some ideas as to a solution but I do not....other than moderating, either with people or algorithms, it is tough. And some categories could use an algorithm but one like photography, how does it know it is a just a pic posted or a true post about one's photography?