Good for players, or good for sales, or are they the same?

Hi Everyone,
I was online yesterday and I read an article on the Mothership that talked about why BFZ is different than Zendikar. It doesn't have certain types of cards and mechanics and it does have certain cards and mechanics.

Mark Rosewater specifically addressed the annihilator mechanic. It's a powerful mechanic and it's very hard to win when your opponent attacks with a creature with annihilator.

The thing that irks me is that he mentioned market research a lot. I think that's a pretty transparent statement that we only want to sell more cards.

The guise is that they are using the research to "make a better game", unfortunately this isn't the case.

The case is that Wizards only wants players to buy cards and they don't care about the game being the best it can be.

I'd even argue that it would be better for the health of the game (maybe not for sales) if they researched the cards that see play. Not just competitive play, just the cards that are played and then identify what players like about the card and why they play those specific cards, then try to design more cards like those.