why standard behavior is to ignore empty checkboxes?

I know that below code do nothing when x is an empty checkbox because the X is not in request.from collection at all and also I know there is html hacks using hidden input fields to make below code usable.

for each x in request.form
 if request(x)<>"" then 
  response.write request(x)
  else
  response.write "not present"
 end if
next

My exact questions are:

1: is this the standard of HTML or standard of browsers (or there is no difference between HTML standards and browsers standard)?

2: Why they ignore sending empty checkboxes when above mentioned code is a basic requirement in programming?