Why did the Monster Manuals for 4th Ed have only the combats stats and other stats relate to fighting them but none of the physcial inform such what the monster look and other such that would help you out with running the monster?
Because when it comes to the physical attributes a picture is worth a thousand words. And they all have colour pictures. They also generally have motivations, lore, and backstories.
Why where the angels changed from looking less like humanoids more like humanoid from the waist only?
More etheriel and otherworldly while at the same time more humanoid which better fits the myths. Win in both directions.
Why is the art work for the angel IMO terrible in 4th?
Pass.
Why did they make the evil deities have there own angels? Evil deities should should have fiends as their servants not angel unless they are fallen angels.
Because it differentiates angels from demons by behaviour. Angels are servants who carry out divine bidding. And when you see an angel, especially a dark angel you know one thing.
just got real. Demons on the other hand are always looking out for number 1. Using an angel as a messenger means that the evil powers have messengers you can
trust - and that's a far, far scarier thing than a demon who might be lying through its teeth about being sent by Lolth or Mugablyet.
Why did they change the alignment system in 4th ed?
Because the new one is much more likely to be shared between different people at the table. That
you can do this for one character shows the problem in applying it to motivations.
The 4e alignment system has a central core of Good/Neutral/Evil based on how self-serving you are and how much you help people. Most people can instinctively grasp this in a way they can't e.g. Chaotic Good. But the Good/Neutral/Evil axis is all people working within the system and just a general marker. Then you have the two 'outsider' alignments.
Lawful Good - the alignment of Paladins unwilling to compromise with the world. And Chaotic Evil that just wants to watch the world burn. Both these alignments are important and
deserve to be put to one side rather than on the 3*3 grid and treated as just another alignment.
Why did they change the Planes from something somewhat like the planes where in Planescape but with some changes in 3rd ed?
Because the 4e planes are much more of an adventurers' cosmology. You start off on the Prime Material plane - with access to Faerie and some aspects of the Unseelie section of Faerie (the Feywild and the Shadowfell respectively). More stories, and a wider range of mythology that can be brought in.
Also the old Great Wheel encompasses everything and is intended to. The 4e cosmology has a Far Realm that is outside mortal ken. It has demons and primordials outside creation and wanting in to tear it down.
The Great Wheel cosmology is good for Planescape - a setting about philosophers with clubs. But honestly, who cares about e.g. Bytopia. Or for that matter the difference between Tartaerus, Hades, and Gehenna.
But the picking out of the Primordials' prison, the demons trying to break into and rend reality, and the Far Realm? Mmm, yes. The cosmology directs you to plots.
Why do some people think 4th ed was trying to MMO-like?
Because of the language used - a conscious decision was made to make the language more MMO like and less tabletop wargame like. Things like the defender and striker role (which had existed forever). And because everyone got to do cool things from their character sheet.
Basically you're finding things about 4e - the early monster manuals were designed to be reference books at the gaming table (there's as much fluff in them as the 2e MM, but a lot of it is contained in the knowledge boxes) - and organisation and tactics is implied by the monster selection. 2e reads better but I can flip to the 4e monster and find
exactly what I want to know.
As for law vs chaos not being explained, the law vs chaos axis
predates the good vs evil one. And is best described by an Islamic proverb "
Better a thousand days of tyrrany than one day of anarchy."
Edit: I've just realised how to summarise the replacing of the Great Wheel. The very name "The Great Wheel" implies that the whole system is orderly - and D&D is a game about conflict. Even the Blood War is ultimately orderly and has rules - and the conflicts are always faction vs opposite faction. "Keeping the balance between good and evil" is a moral good in a Great Wheel setting.
The 4e cosmology is built on a conflict-laden core. Faerie overlapping with the material plane. The Primordials and demons forcing their way in. The Far Realm threatening to knock over everything. Demons trying to corrupt. And the PCs are there not as pawns in a chess game between Good and Evil and one between Law and Chaos, but they are instead the people on site with buckets to bail with and duct tape to try to patch the whole craft back together.
The Great Wheel rolls ever onwards. The World Axis is threatening to topple over.