1.) Flavor is not always the best reason. But I reckon I am not alone in enjoying flavorful takes, and would probably keep decks in-color even if it was changed.
I wholeheartedly agree. This is what separates EDH from other formats, and it's what drew me to the format in the first place. I don't really care how powerful most of my decks are - if they feel like they have flavour or tell a story I'm likely to keep them around. Some of my favourite decks to play lose a lot but are stacked with flavour. I'm not throwing that out the window in favour of powerful decks.
To my mind, there's a couple of points that are crucial in this argument. Firstly, power is not the be all and end all in a format that was designed as a primarily social format (and the EDH rules committee seem reasonably committed to keeping the main ethos of EDH going in this direction).
Secondly, this sort of change will likely result in the sort of environment you see in Legacy and Modern - sure there will probably be some card variation initally as colours are opened up, but inevitably you'll see the same staples come out of the woodwork, prices get driven up, social or casual players get priced out of the format and you're all of a sudden playing a different, far more cutthroat, far less inclusive ballgame. That's not something I want to see, as a primarily kitchen table weekend warrior. I enjoy this format too much to see it priced out of my reach.
This might be a personal thing for me, but I enjoy the brewing stage as much as I enjoy playing. And part of the challenge of that is working around restrictions; it keeps me engaged in the deck mentally, means I NEED to know it in and out to play it with any degree of success, and helps makes the deck MINE; not a staple deck that anyone with enough money can build, it is original to me and the way I want it to behave. And that, to me, is worth far more than having a higher degree of power available.
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Anafenza:Dead.Now shes a spirit
Naarset:became a planeswalker
Sidisi:Dead and revived as a zombie lol
Zurgo:Worse then death,he became a weak coward that strikes bells as his job :/
Surrak:Punching bigger game
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EDIT:http://www.starcitygames.com/article/30422_Preview-Card-Dragonlord-Atarka.html