That's really nice, but there are so many things that people want the Monk to be:
Kung fu interior mystic (See: 3e)
Non-mystical, non-magical unarmed attacker.
A divine-related class. A psionic class. A ki class. A martial class.
A striker, a controller. And you're saying a defender.
There's too much that people expect from the monk for it to all go into one thing. A decision must be made. And it's easier to split the Monk up into different areas than to try and do it either one way or cram them all together.
As to the "asian" power source, you have any idea how much complaining has gone on since the Monk was in 3e? How it didn't "Fit" the "Fantasy Genre" that most people wanted? Same thing. The genre or flavor didn't fit. So the monk/ninja/samurai gets put in its own little area because the "I don't like oriental flavor in my fantasy" is too vocal a group to ignore.
You're dealing with different vocal fanbases that expect different things, and thus the biggest groups will get what they want, not individuals that want it all.
I'm not telling you what I want. I'm telling you how it's going to be. I will bet you cash that market research reflects the above, and what I said here is how WotC is going to do it. No matter individual preferences to the contrary.