I want to say it's because of many things.
Minecraft was what started this sandbox survival craze, paving the way for other games like Terraria, Roblox, and Starbound.
Steve was also added to Super Smash Bros. Ultimate just recently, but that likely just added more players to the game than changed any numbers around.
Don't waste your time with what other people are doing. Do what makes you happy, and play what you like. Nobody really -says- they're quitting Minecraft, because nobody else cares... probably due to playing Minecraft.
