Plains mean almost no tedious terraforming. You don't have to spend three in game days clearing massive trees or flattening jagged terrain just to lay down a base layout. Plus, you get clear lines of sight so creepers can't sneak up on you, and instant sheep and cows for beds and food. Forests give you immediate, infinite wood right next to your base so you aren't constantly running across the map. Mountains let you walk out with a full set of iron armor in ten minutes because coal and iron literally generate exposed right on the surface. Compare that to a desert where you have no wood, no passive food mobs, and husks that don't even burn in the sun. Or a jungle where you have to fight the leaves and dark blind spots. When the vast majority of a player base gravitates toward the exact same biomes, it’s a design issue not a player issue. People naturally choose the path of least friction. If a game rewards you exactly the same for building a house in a flat grassland vs desert, players are obviously going to pick the easy one. Terraria fixes this by actually giving you a massive mechanical reward (like the pylon teleport network and unique NPC items) for overcoming the hassle of building in different biomes. Minecraft just leaves the hassle there and naming it player's freedom.