They are one of very few studios who update their games for years after release. Games make the biggest chunk of lifetime revenue at release. Unless you are a unicorn and have low development costs (Minecraft, Terraria, factorio), you will simply go bankrupt updating your game for free. See the rise of industry dude, made 4 million and now lost his house. Why? He kept funding development for four years without any revenue. Everyone who wanted the game bought it in the first year.

If you want to keep updating your game for more than a couple of months you need cashflow. You have the choice of micro transactions, subscriptions or dlc. You need to do this or go bankrupt.

Paradox gives free content updates along every DLC. I really fail to see how that is bad. The alternative would be to simply release the game, patch it for a couple months, then start working on the next game, like every other game studio. But people would hate that to. You can really do nothing in the games industry without people hating on you.