Considering this for a homebrew setting and would like some thoughts.
How important are the "odd" PC races in an RPG? For example: in the core rules half-elf, elf, half-orc and dwarf are, sorta, just specialized humans, but gnomes and halflings are something different. The Dragon Empire races are, with some exceptions, "odd" races. Does a world, or players, need the odd or at least non-human-ish choices?
EDIT: To make it clear I am talking about PC races.
It depends.
For example, I'm currently playing in a 3.5 game, in which the only PHB race other than humans I am aware of existing is dwarves. And they're not playable. I'm not even sure if they're PHB dwarves; they don't live on the material plane. And the game runs just fine. Of course, we knew it would be a human-centric campaign (set in fantasy medieval Russia) going in.
Somewhat inspired by that campaign, I've been working (rather slowly) on a campaign based on the premise that Atlantis is real, and has conquered the majority of the area around the Mediterranean sea. My goal is to mix history, legend, and magic into a coherent whole. My original plan there was to have only humans, though I expect to treat different ethnicities as different mechanical races (largely similar, but with some differences). (The campaign above has no regional distinctions beyond 1st level class options and some regional feat options.) In some discussions, I've run across a few who don't like to play human. They want to be different. And I got the impression that being able to be an Atlantean or a Babylonian wouldn't cut it; they wanted actual non-humans. So I've been thinking about how I can make that sort of thing available.
In this case, the first step is genie-blood, since I've already determined that the djinn, efreeti, etc. exist. Throw in some half-bloods such as Sylphs & Ifrit, and I'm partway there. I might also use notably different stats for some of the ethnicities, rather than my original idea (which is +2/+2/-2, and a +2 bonus to some skill, with maybe a little more).
So it depends on you and your prospective players. I'm guessing that since you're asking this, you don't feel the need for them to exist. But think about, or talk to, the players. Also think about how culturally diverse the human races will be in the setting.