Forum tagging system isn't the issue here. It's not even remotely technical in nature.

When someone feels the need to write long public rants and derail (good) threads because they feel offended by someone else's post, comment or tag; because they feel they're not respected enough by other members; or other issues that are personal and subjective by nature...

...imho that's a (community) issue at play here, which will not go away if you disable the thread tag system.

And I think they should just use the 'report this' feature if the offensive post/person did not act in accordance to the forum rules, rather than try to rail up the community without familiarizing themselves with all the rules and regulations already in place to handle such issues.