Special:Badtitle/NS90:User talk:New user message/why..?/reply (2)

Sadly, it's not a bot in the conventional sense. It's a script triggered by an extension to create a user page for new users.

However, their is a filter for this:

Namespace: change from "all" to "Main" to filter everything to just namespace edits in RC. Hit Go after making the change to see the results.