Slow down for a moment.
I'll agree that many of the third and fourth generation pokemon are less artistically imaginative then one would expect. But that doesn't mean that the first and second generations are without flaws or that the third and fourth generation pokemon have no amazingly good-looking pokemon.
Take as an examble Ralts, Kirlia, Gardevoir and Gallade. Gardevoir is considered one of the most beautiful pokemon of all time and the rest of that evolutionary line scores high points for their aesthetic.
As for the first and second gen games, how many of you actually liked the design of say, Qwilfish? Or Raticate? Or Magikarp?
The point being that there are no absolutes.