This isn’t us “not getting your argument” but rather telling you that your idea has been tried and it was a miserable failure, for everyone. Even levelers, who stopped bitching about twinks and started bitching about enchants and heirloom gear instead.
Okay, haaaaang on. I wouldn't call the efforts that grew out of the XP-off dark ages a "miserable failure". A lot of terrible work had to be done, but half of that was us fighting issues Blizzard created, and daggone if people didn't experience some amazing games and make some good friends in the process. To be sure, I doubt people would repeat that work if we got segregated again, but I think that misses a larger point.
Competitive twinks were glad for the segregation, because they wanted competitive games. Then we found out the dirty truth about twinking: most of us aren't much better than our XP-on counterparts. No, really, we're not.
All these complaints that levelers have about twinks, including 5p pugmades and unfair advantages? The same thing happened in XP-off queues. A majority of twinks wanted to play with their model cars, and a minority wanted to race. The minority crushed the majority in games. Games ended.
I loved XP-off games, and spent a considerable amount of time and effort to help make games happen during the segregation. But the biggest problem we could never overcome was this differing motivation.
@jwl I hear what you're saying about wanting to get more competitive games and flush out the casuals. I'd support another segregation to see if we have what it takes to lift brackets up. But there are a lot more casuals out there than you may realize. We're talking at least 80%, and I'm one of them. I'm one of the most completionist gearers I know, but when it comes to actual PvP, I'm middle of the road. At my peak I was easily a top 10% RBG'er, but I left those days behind. Many of the veteran players here will tell you they did the same.
I said it years ago and I'll say it again: the difference between casual and competitive twinks is significantly greater than the difference between the average XP-on player and the average XP-off player. As
@Chops said, segregating twinks will likely yield some great games at first, but the increased organizational effort involved will kill XP-off twinking, leaving XP-on exploitation. I'm fine with "great games or no games", but we can find better options.