i see what you are saying, but look at the other side. yoshi stated he wanted 1500-2000 people online for each prime time. that would be 1500 people on for na primetime/ 1500 on for eu primetime/ 1500 people online for jp primetime. your ls would not have to work around schedules for the other time zones because there would be enough people on during each that they had plenty of people to play with. early in the game i had a ls that had 3 divisions with eu/jp/na divisions.
when the servers were populated no matter what time you got on there was people to do things with. i know it's a personal choice, but to me it's more fun to be able to get on no matter the time and have large groups of people to party with than a regional server would be getting on and having 1500 people during na primetime and nobody playing the rest of the day. one way has 4500 people playing over the course of the 3 time zones and the other has 1500.
i'm not saying anyone is wrong for wanting the region specific servers, but just stating why i would choose a global server over it. it's just a personal choice, but it's more to my style to be able to get on and play with people any time of the day instead of that 3-4 hour block most will be playing on their set prime time.