Why not do an Australian GGPO tournament and the players with the most points fight it off on a supergun at a major?
Yeah tried that many times, I've been involved in every single one of these GGPO Aussie comps, from the Kailera days 7 years ago to now (GGPO).
People don't commit, many are no show, like half of the entrants don't show up on time, forget, get the days mixed up, or are way too late, people often cannot connect to players, there are many delays. Getting folks to commit to offline SF2 comp is hard enough (defaults left right and center), try it online... it's really not fun. We would require committed and dedicated ST players, and in Australia there really isn't that many, I could probably count the lot on both hands, not including thumbs, maybe thumbs if I'm lucky (but I doubt it).
If the comp is small like an 8 man bracket, and people actually give a shit and are committed, then it has potential to be smooth, but if you want anything greater like a 32 man bracket, with folks who are casual players, or new comers... it's not possible. It's ST we are talking about, getting online SSF4 was impossible, look what happened to the last online event...