No-one has said that the Ideas forum doesn't get listened to, as this is not the case.
On all of the ideas, where we have said they've been issued to the developers, this is the case. Our Community Manager passes the ideas to the Product Manager, who then discusses the ideas with the developers if she feels that they would merit being implemented. Every idea that we put forward is read, and a decision is made. This decision might mean that the idea is implemented in the very near future, at some point in the distant future, or not at all.
You have to remember as well, that we are not the only community of Grepolis. In fact, we only make up a small part of the overall player base. There are well over 1 million people playing Grepolis worldwide, and we have (according to GrepoStats) 261,269 players in our community. An idea that gets suggested in another community, the German Community for example, which is far larger than ours, might get implemented over one that is suggested by our community.
The developers cannot listen to just one player base, and make decisions based off of that.
You have to realise as well, that the developers will not make a decision that will jeopardize the future of Grepolis. Innogames are in this to make money, they are a business, and they will not choose to lose money by making a wrong decision.
The Revolt system will be implemented on future worlds, but that does not mean to say that it will definitely be implemented on ALL future worlds. I cannot say either way whether it will or not, but it is not a definite 'yes'.