Many new users use the "Answer" section to answer another answer. It seems they (reasonably) assume the Stack Exchange sites work the way many forums and Facebook work: a chronological sequence of posts, whose order is static, so an "answer" posted under another answer would make sense if you wanted to respond to an answer.
Not being familiar with how Stack Exchange works, the "Your Answer" link is the only active link that fits the meaning of "I want to post something".
This is actually not unreasonable, because "Your Answer" is ambiguous: Your answer to what?
Although a bit wordy, "Your Answer to this Question" would make it clear to new users what "Answer" means in Stack Exchange sites (and reduce the number of NAA flags!)
I am not precious about the exact text to change it to, but the meaning should be clear and unambiguous.