Quote from dnLLYeah... I'm sure they have time for this...
4 people are probably better than thousands of people actually trying to adapt to a new meta. Banning the 2 best generals at the same time? Wow. I wonder how much time they put into the format WITH Derevi and WITHOUT Zuur, because there is no actual top-8 that could help to determine what would be the meta in such case. All could be done is assumptions.
And Grim Monolith, seriously? They playtested the format w/o Zuur and Derevi and that's the conclusion? Monolith is too strong? Wow... we should ban Basalt Monolith too now that we're at it. On what is this really based? All decks using it aren't warping the format at the moment of the ban. So it can only be based on the assumption that it would warp the format with Zuur and Derevi banned.
4 people versus the whole duel EDH world. How could 4 people be better at playtesting the meta than the whole rest of us? That's impossible. Even 10 or 20 people. You need more datas.
And why is Zuur so good anyway? There were still key cards to ban in the first place. There are a lot of them. I can't stand playing this format when you ban Edric, Zuur, Derevi and cards like Sensei and Natural Order but not Sylvan Library or Survival of the Fittest.
I guess you really want 2 cards combo to win in the format, like Helm-RIP or even Mikaeus-Triskellion. We will start playing Oloro packed with tutors and those combos and just try to win from there, also winning life every turn.
Just for answer at some of your points:
The 4 people didn't obviously take all the testing between them. Their "assumptions" are taken from MtgTop8, tournaments, forums and from testing on a big scale, so they basically change what the players believe is right to change for making the format better. If you look at Metagame, you can see that Derevi, with 335 played games, is the top tier, and from french forums I know that A LOT of players tested it intensively and came out with the result that she's bannable.
About the Monolith, I agree with Virtus that allowing a turn 3 Iname/Primeval titan/Prossh isn't in the purpose of the format, in the same way that Natural order wasn't. For this reason, Basalt Monolith is legal. Because it cost 3 and it doesn't read CMC0 add 1 in certain cases. It was just one of the rocks that escaped the "first mana accel ban".
I don't know how many members of the WotC are charged for the banlists in tournament legal formats, but following your reasoning, people would have the choice to decide to ban or play what they like. And still, someone in the "minority" would complain in that case.
About Zur: He was being "so good" since 2012, when the format was born. Do you think that Vanishing, Necropotence and Back to Basics were banned for other reasons? From the beginning the comitee is trying to keep contained the power of ZUr, but he still keep to steal top8.