Inb4, region-based matchmaking wouldn't work. There are next to no Aussies who play Uncharted because they're all too busy fanboying over ND and CoD. Even if Oceania is done as a whole, there'd still be a tiny player pool. Just to top it off, if you aren't from New Zealand or Australia, chances are that every other Oceania player you find doesn't have great internet. Even TSD has complained about his own internet and don't even get me started on the lag of the Koreans and Filos when it comes to gaming...
Long story short, blame the continents for being too far apart, if people with bad internet to each other were separated, the player pool would be ridiculous.
I live in Australia as many people know and most Americans I play with only have like 1-2 bars of connection with me. Does that mean our internets are bad? No. It's just the distance.
It's not like no other MP in the whole world lets you play against people from other countries. Like I said, there's still no other MP game I've ever seen that makes people literal gods for having a bad connection, or even remotely come close to doing anything these people do in uncharted.