Auto-tagging is really problematic issue. It teaches everyone, users and admins, to use tags such way that leads to situation where no one is not actually using tags.
Everything just because bot will tag everyhing where is one keyword, even when that post isn’t relevant.
In this topic can found three main reasons to use tags:
- sub-category other than topicwise (like tagging all videos; users seldom searches just videos, so this is just for admin and even he/she doesn’t really needs it)
- detailed search used as menutype element (like tagging iPhone; users never want to find everything under keyword iPhone, they want to know something like why discourse app crashes on iPhone)
- vertical taxonomy expanding categories using structure that helps a user, not admin as tagging is quite often builded (that can’t be automated easily with normal tools, perhaps somekind AI can solve this out someday)
Because of constantly misuse of tags, tag pollution and hashtags like Instagram, users have learned not to use tags. Tags should narrowing hits, make things more spesific, not expanding.
This topic (and Meta itself quite often) is an good/bad example. How many relevant used tags you can find?