I'm no sure if there is such a thing as "objectively good RPG design" when it comes to RPGs, everyone has their own personal opinion, and everyone has different tastes. But Erik is nonetheless someone who knows games. It is my opinion that his breadth and depth of experience gives this list an objective view of game design needs. Applying them certainly has lead to easy and quick games that are fun to play.
Without further delay I leave you with the 7 things Erik wants from an OSR ruleset, aka "The Tenkar Test"
Thanks Erik for laying it out so well, your points have been most helpful!
The Tenkar Test
1 - A front end as crunchy as the players want it.
2 - A back end easy enough for the DM to run with minimal reference to charts, tables, monster descriptions, spells and the like.
3 - Whittled down to it's core, a DM should be able to run the game with a 8 x 11 sheet of paper.
4 - Players should have everything on their character sheet that they need to play a session.
5 - Spells should be simple enough to explain in 2-3 sentences.
6 - A unified skill mechanic.
7 - There should be a Player's Section and a DM's Section in the rulebook.