The thing that irks me about the lack of playable kobolds is that I walk around the Harbor and the Marketplace and I look around. I see humans, elves, dwarves, warforged, a few halflings, and... kobolds and bugbears?!
They're everywhere. Perfectly integrated with society, standing around training adventurers, selling items, trading collectables, even running the auction house.
Why can an adventurer, who is supposed to be an extraordinary and unusual person, not be of a race that's apparently commonly accepted into society around Stormreach?
If they hadn't done this, I wouldn't have any problem with them not including playable kobolds.