gkrit, being right on the money, is saying that you can't take all the successful ingredients from previous games and put them all togheter in a new one. Just because they were awesome in previous games, does not mean they will mix in a good way for the new game. Different new games will adopt different features of previous games.
I for one strongly disagree with "winding down" graphics. The beauty of the graphics is what sold this game to me. If the producers cheapen the graphic output of the game, then yes, it will be playable on more computers, but that is not the same as selling more copies of the game because you will also lose customers who now think that it isn't worth the money. I trust that GPG will make the right decision there.
And now I am going to say something that I think many will not agree with. The performance of this game, ie the graphic output, is not a problem that needs to be fixed. Yes, there is a problem in 2D - many who could run it previously without hickup, suddenly can't. However, I can run this game on a LAPTOP that is 3,5 years old. You can't lessen the demand any more than that. There has to be a cut-off point, and I say it is a good cut-off point at the moment (not counting the problems 2D brought).
With that said, if there were options to reduce the graphics in order to gain performance, then I don't think anyone would mind being given those options. Just don't force them on all of us.