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>