When in the future the same happens to workers - when most workers are terrible at the (very few) skills that are still needed and nobody wants to hire them - then we'll have a problem.
Well many people find the level of inequality in the economy surprising, but it really isn't that surprising it occurs in app stores. Even if we discount all the apps that are objectively terrible, the system very much favors apps which are already successful.
And I'm not saying that it's a bad thing. Why would you want to download some obscure game with 2 reviews over the game your friends are playing and you know is good and successful?