The versatility of a wizard being able to learn every single spell trumps the hell out of the extra spellcasts per day a sorcerer gets. Having played both, I can confidently say that being able to prep spells for anticipated scenarios trumps the hell out of being confined to a tiny list of known spells that you have to make as general and non-specialized as possible. Also, metamagic feats all became full round actions for sorcerers, or some such prohibitive crap.
The one and only time in all the games of DnD that I played where a sorcerer trumped a wizard was the time our entire party got dumped in the ocean. I was able to spam all my upper level spell slots into dimension door to save half the party from drowning by popping them to the beach.