Well yes and no. They were very few good blog focused CMS at the time. A contemporary one that comes to my mind and that actually predate Wordpress was Dotclear (which is still alive and still focusing on blogging). More general CMS like Typo3, Drupal, SPIP, Plone to name only a few open source ones were already around too and much more capable than Wordpress was.

What Wordpress did very well at the beginning, was focusing on one thing: blogging for non technical people. It was a much more limited software but that made it much easier for so much people. And it came exactly during the blog boom and only with time became a more general purpose CMS. But if you had to build a website for your business it was a very bad choice at the time.

Bottom line: making good software is one thing, but timing is everything.