Vanilla WoW had some pretty over the top UIs

Honestly, Still this UI looks a hell of a lot better than many of the UI's I see today. unlike a lot of UIs it actually leaves the center clear, which is really all that matters. Generally terrible UIs are the ones that clutter the whole screen to the point you can't see your character.

Decursive...we meet again. Simpler times. prior to patch 2.0 addons could target and spell cast with few restrictions. So these routines could be run from slash commands which will target and spell cast all in one click.

This means there were also addons that would target someone with the lowest HP and heal then accordingly. again, this became impossible in 2.0.