SimpleFormController is very old and the current hander mapping approach
you should be using can't even really be compared to that easily. I would forget about SimpleFormControllers and focus on understanding the current way to do it.
When Spring registers this Controller bean it will scan it for @RequestMapping methods. These methods can define certain attributes to narrow down which method is the 'best' match for the request. The first obvious match is the URL which you have in the value. After that you have specified a request method of POST. What this means is only execute this method if a request comes in for /logout.htm and only if it an HTTP POST. In your case your were hitting that URL but it was an HTTP GET because you were clicking a link not submitting a form. This is what E Armitage was trying to point out to you. So the solution is either to change the controller to expect a HTTP GET or to change your
JSP to call the server using and HTTP POST.