Grammar has necessarily conservative conventions.  Of course, conventions should be reviewed for purpose and effect.  The purpose for spacing is for improved readability, or faster comprehension.  As an example, youcouldstringwordswithoutspacing.  This lack of spacing between words slows comprehension, because you have to separate each word mentally.  Each word represents a discrete idea.  Extending this spacing concept as a method of compartmentalizing discrete ideas for faster comprehension, a period and double-spacing aid comprehension by separating one complete thought, or sentence, from another, which gives reason to pause and consider its plausibility. 

or you could get extreme (you rebel, you) and abandon grammar altogether like e e cummings and adopt a stream of consciousness just dont expect others to understand you better good luck
Wink

Cheers,
Jason