There's more to it than that. They've re-released edition after edition to obsolete the previous. Used to be 1 mana got you a 1/0 or 1/1 creature with nothing else. Now you can get cards with 1 or two features, flying etc. Anybody using the old ones is a sucker. Its easy to think its all about the money, you have to buy new cards to keep competitive.
In fact this is why our game club designed their own card game (Orion Empire, check it out on Kickstarter!) The idea is, new cards will always be different in some way from old ones, so no card is ever completely eclipsed. So you can buy new decks to keep it interesting, but your old one is probably still competitive.
In fact this is why our game club designed their own card game (Orion Empire, check it out on Kickstarter!) The idea is, new cards will always be different in some way from old ones, so no card is ever completely eclipsed. So you can buy new decks to keep it interesting, but your old one is probably still competitive.