Second, I realise that I would never want people to be allowed more than one character per server. Otherwise every man and his dog would roll themselves a crafter for their own uses, and the economy would be so much weaker. Even if you needed to hit level cap to do so, I can see tons of people investing the required 120 hours.
As an "altoholic" of the worst kind (In other words, I enjoy creating a -huge- amount of new characters), I have to disagree with this statement. Creating other characters brings a new approach to the game - even in Oblivion/Skyrim, I occasionally find myself creating a new character to get a different point of view to the game.
After playing World of Warcraft for two years and filling all my character slots on my favorite realm, I began to lose interest in the game; I could not create any more characters, I found myself incapable of playing on non-RP realms and I had grown accustomed to the community of the realm I was playing on, and I couldn't bring myself to delete the characters I had achieved so much on. This lead to increased boredom to an "altoholic" like me, as I had so many different characters I would have wished to try out, yet I just couldn't due to the reasons I mentioned.
It might indeed make that one character more valuable if you could only have one character per server. Though, it would take away a large aspect that makes playing games fun; Re-playability.
Re-playability is perhaps one of the most important aspect in a game. What makes you hook up into it, what makes you spend hours after hours playing a game, what gives a broader view on the whole game?
I found low-level content in World of Warcraft rather enjoyable myself. The end-game seemed a bit dull, but low-level kept me most interested in it. You actually had to do something, had to see the world and do quests. Something that was missing from the end-game - other than the "daily quests", of course, which felt more like a tedious duty than a fun hobby.
So, the point of this post, although biased by my past experiences of WoW - something often downgraded in societies not associated with it - is that there would be a need to creating more than just one character per realm. You are free to stick to one character if you wish, but why not allow others to create more? Even if they are only for profession farming, how does it affect -you-, mm?
Even as the text here might seem accusative, I am actually writing this - as most of my posts - from a neutral view.