Re: Gravitational force equation: how convenient. Why?

Wow. That is a very thought provoking question. There are
many explanations for why so many of the laws of physics and
astronomy appear so simple. For one thing, realize that most
of the Laws like Newtons's Law of Gravity are actually 
approximations. Einstein's General Theory of Relativity, 
which involves much more complex math, is a more accurate
description of Gravity and space-time and physicists are 
STILL trying to understand it better. Quantum mechanics 
involves the study of the interactions of matter at the
sub-atomic level which is a much more precise description 
of other simple concepts like how a prism disperses 
light into a rainbow. 

So when trying to understand a physical process, scientists
will usually consider the simple explanation (Occam's Razor) 
and then build it up in complexity the better explain all
the observations. Most physics and astronomy is really complex
but either you don't get to hear about those details or
we have not quite figured them out yet. 

The Universe is a vast, mysterious place.