I've noticed that people have been abusing forum tags to anonymously insult the content of a thread and/or its creator, express negative or derogatory opinions, and/or otherwise are just not being used for their intended purpose of making it easier to find specific topics when searching.

This thread is a great example of such.

In the current state of things, you can only ADD tags, not remove them, which means the trolling/useless tags will just remain indefinitely. That said, if people are abusing the system it should either just not exist (Since it's not that helpful to begin with) or make tags removable so people can moderate them and help ensure only ones that are actually helpful/relevant remain.