I keep seeing this response over and over in this forum.
Instead of blaming the new users, why doesn't someone just remove the "New Topic" button from the https://forum.arduino.cc/ page?
The only reason users are posting in the unspecified category is because there is a big button on the main page that says "New Topic," which posts directly to the Unspecified topic. Just remove that button already...
When you use that button you still have to choose a category. If people would read the selections instead of just grabbing the one at the top we wouldn't have that problem either.
To elaborate on what @Delta_G said already, this is incorrect. When you click that button, no category is selected:
If the user attempts to publish the topic without explicitly selecting a category from that "category" menu, the forum software will block the publishing with a "An error occurred: Category can't be blank" dialog:
So the only way someone can publish a topic in the Uncategorized category is by selecting that category from the menu:
We created the Uncategorized category because previously when people arbitrarily chose the first category on the list, the miscategorized topics ended up in the IDE 1.x category where it was less likely that the moderators would spot them since they were mixed in there with topics that are actually about Arduino IDE 1.x.