As legendofa already touched on, there are a number of defensive cards getting printed. The fact that they are not the priority does not mean this aspect of the game is forgotten - just that it does not appear in significant volume in any given set.

One more point to add to the above - Limited. Defensive decks do not work well in Limited - the round timers in limited are too short and you are not as likely to draft something to close the game. Short times, slow gameplay, and lack of way to close out the game are problems.

Paradoxically, the problem can get worse the more you try to fix those things - increasing the power and frequency of defensive strategies can mean two people decide to draft that strategy or build it from their sealed pool. What does that mean? Mirror matches, where both players lock down the other. I’ve played defense in that environment - I’ve seen games where a player won because the other drew from an empty deck and I’ve played in games where the end of the round was a single tied game, since the first we played went to turns and no one won. It is not fun for anyone.

One final thought, I feel for a number of the threads you make asking why something is, the answer is often “this is important for creating an enjoyable Limited environment.” I am guessing Limited is not a format you play very much (that isn’t meant as a slight - people are welcome to enjoy whatever format they want). Still, I think it would be helpful to ask yourself “is there a Limited reason for this design choice?” when evaluating MaRo’s blog posts.