It's the old Magic Nerds vs Magic Jocks thing, even in FR Lore a lot of Wizard dominate nations don't like Sorcerers, Thay, Halruaa, perhaps others. Clerics tend to view Favoured/Divine Souls Sorcerers simularly, sometimes. I'm trying to think of a single FR nation that perfers Sorcerers, but nothing comes to mind. I do some research.I would tend to believe many wizards were likely actually jealous of sorcerers. Here they are, studying for hours, poring over dusty tomes, trying to master how to cast a simple spell, when it all just comes naturally to the sorcerer. Add on the fact that a sorcerer can cast more spells per day than a wizard of the same level, and the jealousy only increases. It's not particularly surprising, then, that those wizards would project this jealousy into scorn - better to look down upon sorcerers in disdain than to pine hopelessly to be one, knowing you just don't have what it takes for spellcasting to come that naturally to you.