At the top of the question, we have:
and at the bottom we have
Sometimes the question can be very long and these two boxes can be very far apart. If you come from somewhere else (for example, via a link in the inbox to a comment) then that puts the "Ask another question" link much closer than the solution (the list of duplicates).
If I came via the question list, being as I don't (yet) know if the question relates to me when I'm at the top of the article, I'm likely to skim over it first to get to the end.
Furthermore, the first duplicates box is smaller and the title text (although bolded) is also smaller than regular text. To me, that looks like a box you're supposed to skim over, like adverts that interrupt the flow of an article. Whereas the box at the end is larger, and visually draws the eye as it is significantly indented and, besides, there's a natural pause that one does when one gets to the end to reflect on what you've read.
Apologies for the multi-barrelled question, but I see them as related:
Why is the line "This question already has an answer here:" smaller than the text it describes?
Why separate these two pieces of information?
Can we list the duplicates in the duplicate closure box also, so that "ask a new question" becomes one option of many?