I think the biggest problem facing most new users of Drupal is understanding exactly what they want out of categorization.
Nine times out of 10, people just want a simple navigation system, linked to a series of static pages. I'm sure that Drupal can do this, but with some effort. The problem with Drupal is that it is way more powerful than a simple static page delivering engine. Although this may be true, it is important for people to be able to start somewhere, and then realize somewhere down the road that they can expand their site to include the powerful features of Drupal with little effort.
Now, the biggest hang-up I can see with Drupal (I'm a very inexperienced Drupal user - a day and a half) is the characterization of categories. It looks to me like Drupal has been struggling with this for some time now. It would be nice to have a clear picture of what categorization can do.
I would like to show a example site that would demonstrate what I typically expect out of categories. I would like to start a conversation on what people expect to see on their sites, and how they describe them. It is not necessarily easy to do this. The example below is very terse and obviously could contain a LOT more functionality, but the fundamentals are there.
I don't ultimately know whether Drupal will be able to perform this way (easily). But if there is a way to categorize content, then more than likely there will be a way to organize a site such as "Joe's Online Coffee House".