I only admin people who I can call my friends.
Well, online friends.
All my admins I play other games with and talk to regularly.
Also, they had played my server for a long time, they had been regulars for at least a month.
You don't really earn admin on my server, so to speak, because that sounds like it's something to strive toward you are just deserving of my trust as a good person.
Hell, Quantum Eagle, one of my admins, isn't too great of a builder but still has his place on my server.