Basic Geography

Why does basic geography in the Marioverse change from game to game? People say to fit with the plot, but still. Like how many castles does Peach have? Is it like Zelda where it's ALWAYS a different Link and ALWAYS a different Zelda? How do they get away with making so many references to other Mario games when it seems like they can't even keep basic geography the same? Not to mention in Galaxy 2 the castle is portrayed two different ways: one is in the beginning in the background of the 2D sidescrolling part, and the other is the 3D one Bowser attacks. Plus, the first one had NO town nor waterfall or moat, AND it had to pillar-like objects in front of it.
It's the same as in cartoons where any major event from one episode goes completely unmentioned and unreferenced in other episodes. It's not a big deal.

Also, this belongs in the Marioverse board.