I think you're missing the point that it is defined, the current html5 spec says that <title> implies the existence of <head>, <body> implies the end of <head>, body tags imply the end of <head> and the start of <body> etc.
HTML5 is not XHTML.
<!DOCTYPE html>
<title>Title
<h1>Heading
expands to
<!DOCTYPE html>
<head><title>Title</title></head>
<body><h1>Heading</h1></body>