Didn't read all the thread, but I'll throw in 2 cp anyway.
Isn't a lot of this a perception of
Opportunity Cost?
For example, if I want to build a big-tough-brute, my racial choices incur an Opportunity Cost (OC for short). If my choices are human, elf, dwarf, and halfling, my choice is pretty easy; its going to be human or dwarf. All that matters is specific racial traits (bonus feat, or con bump for example).
Now, add half-orc, half-elf, and gnome to the mix. Suddenly, my OC raises because of half-orc (the quint brute race). I might really want that +2 Str, but do I want to give up that +2 con or bonus feat?
My OC rises further with every optional race that fits the brute role: half-ogre gives strength AND con, but at an LA. Minotaur is really awesome, but has racial HD. Orc is stronger, and dumber, than half-orc. Goliath is kinda like a Half-ogre but with a reasonable LA. Etc, Etc. Maybe I want the minotaurs cunning, but I really like the visual of a half-ogre, for example. And my NEXT PC is so going to be a goliath druid...
When there was four races, the OC was the other three races. Since two didn't fit, the OC was really the other one (dwarf or human). Each new race adds another OC, since if I pick human (for example), I'm not just skipping dwarf, but also half-orc, half ogre, orc, goliath, etc all of whom would have fit my "brute" role just as well. (Or a lot better than elf would).
So the idea that added choice brings unhappiness is rooted in the "roads not taken", if your only choice for a brute is four races (two of which don't work anyway) then picking human over dwarf is mildly low OC. If you have dozens of other races mentioned above, the OC raises with each race that could've done the job well too.
The trade off for getting the "right fit" I guess...