Took me less than two hours to level a rattata to 100. I saw hundreds of people when I got to Hoenn yesterday... I even got a shiny rattata out of the whole thing. With the amount of time it takes to construct a forum post, you could have probably had one at 50 minimum.
I almost guarantee the gating mechanism is in place for server stability. If everyone immediately went to Hoenn, the servers would have not been able to handle it. Besides, this is one of the least grindy tasks I've had to deal with in this game...
Staff confirmed the gating mechanism is in place for server stability. It's less of a 'troll' and more of a 'gimmick' as a solution to the problem you described.