Paradox's model isn't something I'm overjoyed about, but at the same time there're worse models out there, and the base game gets significant, game-changing, updates even if you don't buy the DLC.
Yeah, and the cool thing about the free updates is that modders can use those improvements to further add to the game; take the artifact system coming with M&M - most of the Paradox-made ones will be in the paid DLC, but the system itself is part of the free update. This means modders can use it to add proper items that previously may have existed as traits and thus cluttered the trait screen.