Trust me B&K I get where your coming from and your right its not a MUST have but I still disagree with the pricing for something so minimal.
I disagree on both counts. The supplement is 121 pages long. That actually makes it longer than the actual codex itself. Additionally, they're providing Altar of War, an iPad only DLC for codexes to date, included. That means for something larger than the codex it is still the same cost, along with additional content that runs for an additional $7.99 USD.
I'm going to have to say that looks like a pretty fair deal to me.
For example if GW is going to put out say 5 supplements for the Eldar, they could have put a nice book of back story together with those 5 supplements. then have 5 small books with rules and pictures for the people who just play the game.
Again, I still disagree. This is obviously designed to pander to people who like Iyanden, want to play a "proper" Iyanden army and that's fine. I'm sure some crunch players will get their fill out of this too, but it's something that isn't geared towards the average player, but rather someone who feels strongly about their army theme.
And not only is that okay, it's frikkin' awesome. Consider the possibility for the big factions to have all those flavoured armies out there. Proper representation for White Scars, Imperial Fists and so on. Could you collect every single one of these books in addition to the codex? Sure, but it's really meant for the players of those specific armies who want to take playing their army's theme a step further. People who want to do more than just play Marines who are painted Yellow and call them Imperial Fists but who want to actual rules to get the proper "feel" of their army on the table.
That way you can buy both if you want too, or if you can only afford bits at a time you can do that too.
I wont support these supplements the way they are I would much rather borrow them for the 10-15 pages I actually need.
These expansions are made primarilly for the player who wants to make their army just a bit more "fluffy" and flavourful. I see this as an exceptionally good thing. Sure some crunchier players will pick them up here and there, but splitting the book just seems unnecessary because you're making the ones who want an army that's just a bit more fluffy to pay more to field it than the crunch player who only buys the rules.
Besides, I don't hear people complaining that they only want the rules in their codexes or FW books, so I don't see why we need to suddenly switch here.
EDIT: Forgot that 121 is the number of pages in the supplement on the iPad. Rumours are claiming 32 pages for the hardback.