No, there's no technical reason for that, except what was explained by other ranchers in your other post. Most of the time, you'll do the same thing in doGet and doPost, so one trick is to put your logic in one of both. The other one just calls the one containing the code. In this case, it doesn't matter whether you put it in doPost or in doGet.
is the same as
What the whole thing means is : do the same useful thing whether the request is a GET or a POST You could even do it like