I can see why they would complain about the scrolling within a page as some pages can be quite long. But you would assume that a user would then look for a tool bar such ‘in this atricle’ to solve this issue? Hmm, maybe a sticky header for the ‘in this article’ would be a good idea to show users that this is a added feature. However, this could impact users on small screens such as tablets or phones, so the design would have to be considered thoroughly.
This is just a suggestion