I'm thinking more in terms of human society. STEEM is just 4 years old, but would you put a 3 month old in charge of it? A baby ruling a kindergarten.

50% of STEEM age would be a better guarantee. Of course if STEEM was a 100 year old community, a 50 years old mininum account age would be too much, so a limit on the requeriment could also be established.

Something like: At least 50% of STEEM age or 10 years. A very stong barrier for newcomers.