Note that $1mil lifetime revenue is a very low boundary. A very small consulting operation of 2 or 3 people could easily hit that in a year or two. A single freelancer could probably hit it in 4 or 5 years. It's easy to read "a million dollars!" And think "we're rich!", but running any business has a lot of overhead.
The limit is $1 million per app. How many games make more than $1 million throughout their lifetime? 99% of developers won't ever have a game earning that much.
At the same time, 99% of game revenue probably comes from games grossing more than $1m.