In terms of ease-of-install and basic user interface stuff, I remember it as a substantial improvement over most of what people had been exposed to.

Mind you, I hated it passionately from the first time I was asked to do anything more involved than installing it and switching a theme, and I've never had any inclination to use it on my own time, but I think it's easy to forget that the bar was pretty low when WordPress first came on the scene.