Oli -
I hate to say it, but just because the usual tournament organizer have enough games doesn't mean they're best suited for the job. I"m sure there's plenty of us out there who would volunteer for this duty but can't because we only play 1 or 2 games at once.
Using myself as an easy example: I joined the site almost 4 years ago now, yet I've played only 40 games. However, most anyone you ask will tell you I'm an avid communicator, a quality player, and someone who's usually around a decent amount. I think you'd be hard pressed to find people who would say I'm not qualified to moderate a game. And yet, I've never created my own tournament, and I don't have the 50 games required (and won't for probably another year based on my current loadout of games).
On the flip side, there's people on here who play *way* too many games at once, barely talk in them, and are absolutely terrible quality players, who have way more games than me. Determining who can be a moderator based on game count is implying that those people are more "worthy" than players such as myself, which, while I don't want to toot my own horn too much, seems back-assward.
I think Ruffhaus has a good idea. Why not have people apply for the privilege? The group of people who actually play in SRGs and Tournaments on here isn't that large anyways, so since this feature is geared towards that group, why not let those who want to participate ask for that privilege?