This isn't true with big publishers - Square Enix's $10-14 games are consistently in the "Top Grossing" list. For smaller devs who can't market well, you're right.
http://www.metacritic.com/browse/games/release-date/availabl...
They do aggregate scoring and have established themselves as the main way to rate "greatness" on PC and consoles, going as far as landing game directors a bonus if their creation gets a score above 85. They're quite valuable for iOS as well. "King of Dragon Pass" gets a 90 at MC.
Most critics review games based on what they are. So a simple jump&run game might rate highly if it's a truly original+fantastic one. I would suggest you go through the list - anything above 80% is a game absolutely worth your while - then see if the genre and complexity fits you.