I made a similar statement way way up in this mega thread. By making the brackets closer to a particular guild (albeit with lesser rewards a la Ogunther idea # whatever it was), this would incentivize a rank 1000 guild to pay more to be tops in their class. Which would create more revenue for the devs. Would they get the top tier rewards for beating guilds within their vicinity? Nope. But they could get the best of their bracket through this sentinel program and putting money in. We would still have top guilds duking it out for the best rewards. No holds barred. No "oh poor me."
But the lower guilds still have something to fight for. Something to hang their hat on and say "yep, this guild is headed in the right direction. Maybe with our concerted efforts, we could take on the next bracket with higher rewards." and...you guessed it...put more premium currency, become more loyal to the game, become the next group of heavy hitters.
Meanwhile some groups may try their hand at the top bracket and go "whoa...we aren't ready for this" and instead of phoning it in for the totality of GW, they'd move to a lower bracket (lower rewards...can't stress that enough) and put in a concerted effort yet again. Everyone finds their own "comfort zone" in this case. With those who put in the most effort getting the most rewards.
With this current set up, I don't see that happening. Many guilds will not participate simply because the rewards are the same for rank 1k or rank 10k. They'll put in minimum effort, and therefore minimum money brought into the game.
I hope none of what I just articulated sounded like a "pity me" post. It's completely health of the game and business related.