You could say the same thing about Minecraft when it first debuted (and in fact, many people did). And yet it went on to be a highly successful theme that has lasted over five years.
Modern video games tend to be a very different beast than movies when it comes to licensing, with the biggest success stories not always that predictable prior to release but often having a long "tail" (the persistence of a game's popularity after release), ESPECIALLY for games like Minecraft and Overwatch with both a robust multiplayer scene and a steady stream of new content and updates. As such, it's probably a safer strategy for a company like Lego to wait and see which games can maintain their popularity in the long term before jumping into a major licensing partnership. I wasn't saying they aren't going to sell well, just that there's not as much hype for them.