That's your opinion. I prefer to keep my team together and train them to the max level. I don't want to start anew and assemble a brand new team, and I don't mind collecting a few million XP to level my Pokes. I don't think that it should be possible to reach max level overnight, and more level means more work. You don't have to grind all the levels in Digletts Cave, you're not obliged to reach max level as soon as possible...
For Hoenn, I think the idea is ridiculous, that you have to start all over again, once you get there. This means you trained your elite team to max level and now you have to leave them behind until you return to Kanto/Jotho, so you never have the chance to use them in a Hoenn gym battle. This means that you will get a Hoenn starter for free, which would destroy their value instantly. You know that Frafech'd worth nothing, right? The only difference will be that 1/3 of the players will get Mudkip, 1/3 Torchic and 1/3 Treecko for free. And finally, this would make Hoenn unplayable as an initial region. Because I presume, if you can't take your Kanto/Jotho Pokes to Hoenn, then you shouldn't be able to take Hoenn Pokes back. Not to mention how serious limitation this would mean to the market and to PvP as you can't have your best Pokes from all three region in the same team...
For Hoenn, I think the idea is ridiculous, that you have to start all over again, once you get there. This means you trained your elite team to max level and now you have to leave them behind until you return to Kanto/Jotho, so you never have the chance to use them in a Hoenn gym battle. This means that you will get a Hoenn starter for free, which would destroy their value instantly. You know that Frafech'd worth nothing, right? The only difference will be that 1/3 of the players will get Mudkip, 1/3 Torchic and 1/3 Treecko for free. And finally, this would make Hoenn unplayable as an initial region. Because I presume, if you can't take your Kanto/Jotho Pokes to Hoenn, then you shouldn't be able to take Hoenn Pokes back. Not to mention how serious limitation this would mean to the market and to PvP as you can't have your best Pokes from all three region in the same team...