According to Skip Williams, as quoted in RPG Hour: Third Edition D&D Sorcerers Fri. July 20, 2000*, there were three main reasons for the limited number of spells that sorcerers know:
- The designers wanted the decision between sorcerer and wizard to be a 'hard choice'
- The sorcerer is designed to appeal to a certain type of player, who prefers a more limited selection of spells.
- The idea of sorcerer as "natural" spellcasters suggested a more limited spell list to the designers.
These reasons can help us understand why spontaneous spellcasters lose out on a level compared to prepared spellcasters. It is reasonable to assume that the same design philosophy lay behind both limitations (limited number of known spells and later acquisition of spell levels).
Long version follows...
3e sorcerer design philosophy
The key citation to support the three points above follows. TheSage is Skip Williams.
Shane_M: Why do sorcerers have so few spells that they can “know” and does that number increase with Charisma like spells cast does?
TheSage: Three reasons. First, there has to be a hard choice between choosing a wizard and a sorcerer. Second, the sorcerer class, as I mentioned earlier, is for players who don't want to mess around with piles of spells. Finally, the class concept, a “natural” spellcaster, lends itself to a small, personal bag of tricks. Sorcerers do get bonus spells for high Charisma, but that's only for the number of spells they can use each day. Their selection of spells is fixed (though it expands with increasing level).
Point 2 above is further explained by the following exchange from the interview:
Guest47: Why would someone want to play a wizard now over a sorcerer (outside of roleplaying)? What is the downside of sorcerer?
TheSage: Wizards are much more versatile than sorcerers are. A sorcerer has a very small bag of tricks. If you're they type of player who only uses 3 or 4 spells of each level anyway--the sorcerer is made for you. If you've taken some time to study the spells, a wizard is going to be more to your liking, especially in the long run.
Later acquisition of spell levels
The only weakness of this interview is that it does not specifically address why sorcerers start gaining spell levels at a later character level. In fact Skip Williams avoids answering a question about this:
Guest47: Any chance of getting some specifics on a sorcerer? How many spells can they “know” per level? What is to stop them from learning beyond that limit with a scroll?
TheSage: Yeah, in about three weeks.
Three weeks was when the 3e PHB would hit the shops.
Nevertheless, the interview shows what kinds of design decisions probably influenced the slower spell progression for sorcerers. Williams does not say, "Sorcerers get 2nd level spells at 4th level because...", but it seems reasonable to assume that the design motivations were similar to those explicitly stated for the limited number of spells a sorcerer gets.
The value of this interview
This interview is a great source as:
- it contains the words of one of the three 3e designers
- it specifically deals with the relative weakness of sorcerers over against wizards
- it is contemporary to the very start of 3e, and so to the introduction of sorcerers into D&D
Did the designers 'hate' sorcerers?
There is nothing in the interview to suggest that Skip Williams or anyone else 'hated' sorcerers, unless you interpret the following quote to be an expression of dissatisfaction, especially the last sentence.
Dark_Blade: Besides versatility, are there any other advantages a wizard has over a sorcerer (And I mean anything)?
TheSage: Yes. Wizards pick up higher level spells sooner than sorcerers do. Sorcerers cannot specialize in a school the way a wizard can. The new game as something called a Metamagic feat that wizards can use more easily than sorcerers can. Also, let's face it, having Charisma as you prime requisite isn't exactly a great deal.
*I apologize for using a direct document link, but the directory http://www.wizards.com/chat/logs is not accessible.