We've seen that potential in every CSI except him. If Greg wants to be an Asst. Supervisor or Supervisor then he needs to start stepping up to the plate and show he can do it. (however, I don't see that happening as the tptb and writers probably won't write it.) Not EVERYONE is capable of being a leader and I think Greg (as he's been shown and written) is one of those people. It's not a bad thing or a jab against him, just that not everyone can be a leader.
I'll agree with this. I myself do not know if he's leadership material. As Smokey said in her post, we infer want we want. I would like to see him try. Doesn't mean he'll succeed, but trying never hurts. (Well it can, but that's a different issue... :lol And I don't take it as a jab to the character. You're right. Not everyone is a leader.