I see the logic, and to some extent agree with it, but in principle, I would never like to see this implemented.
I'd like to throw two things out there, from my perspective. Pakarro, if you know anything about martial arts, then you would know about judo. It's the second most widely played sport in the world, and is an extremely difficult competitive sport to master. Many of the recent Olympians and national champions actually DO have master or doctorate degrees in the computer, physical and biological sciences. It IS possible to have both intelligence and physical prowess. It's just not universal. And if you look at the broad range of players in the game.. it's not universal there to see characters who do both magics and melee.
If you're going to cap stats on the basis of magic and melee, you might as well say crafters can't max either, because they'd be spending all their time perfecting their craft, and not training anything else. Sure, it might be more "realistic" but it will also make the game a lot less fun for people.
Secondly, I'm one of those players trying to gain high stats if not maxed in everything. I defy anyone to say I don't RP though. It's a hard balance to try and find time for the grinding I actually enjoy doing, with the people I enjoy talking to and interacting with. Some days, I want nothing more than to sit in the middle of BD1 and whack ulbers for an hour or two while chattering OOCly in guild and alliance and gossip. Some days, I want to run rampant through the city sowing discord and others, I want nice, simple RPs. As an active player in an RP game, I think it should be my decision how I chose to spend those hours, provided I'm not hurting anyone else's experience. And it's not hurting someone else by me sitting in a wilderness training, anymore than it hurts mine by someone sitting at a furnace.
If you insist upon imposing restrictions like this, you will run players off to other games, where they can grind to their heart's content, without people whining about it. And it won't just be the PLers who leave, it will be the people who choose to explore every side of the game, but find some of them summarily closed to them.
Imposing restrictions like this hinders character development over time. It means whatever path you start on, you have to finish. Lets say your character trains up as a soldier, maxes the physical sides, shutting down the intellectual and magical areas. Then they go into some RP war, and end up emotionally scarred so that they can never lift a blade again. Welp, they're screwed from a stat standpoint, because even if they would want to have that change of heart and go the way of the cleric or priest or healer, they can never actually have any decent stats to back them up. And we all know how people love to complain about characters that are RPd beyond their stats.
I just don't see this being a good idea, even if the motive behind the thought is a good one. I think there are other, better ways to try and accomplish the main goal of this game.