A racial writeup for kobold PCs has not yet been published (nor has one for bugbears, hence them having oversized weapons). So first you have to show that kobold PCs actually lack darkvision.
Now, I wouldn't be surprised if the final kobold PC writeup lacks _shifty_ in its current incarnation, moving to something less at-will.
Lacking shifty is not a problem. All that means is that the kobold will have slightly different moves in combat. Not being able to see in the neighborhood where you supposedly grew up is a problem. In that case, we have to explain why the PC kobold lacks darkvision, when seemingly other kobolds do not. Even if the kobold writeup is only used for NPCs, it's still a problem if you apply it literally, and suddenly you have NPC kobolds who also cannot see in the kobold tunnels.
The minotaur thing is less of an issue, but it's still annoying. PC minotaurs should be able to use weapons off of dead NPC minotaurs. Apparently, that's not a problem since the MM minotaurs use normal-sized weapons. However, if they are led by an NPC minotaur with an oversized weapon, the PC can't use it. If it's an ability unique to that NPC, that's not a problem. Strong minotaur, I guess. But the ability applies to all NPC minotaurs. How is it, then, that all NPC minotaurs, regardless of role or other abilities, have this ability, but PCs do not? It also raises an interesting question... do you allow monster minotaurs to wield oversized weapons? If not, the only problem is inconsistency. Minotaur brutes, apparently, are not as boss as minotaur rogues. If you do... then we're back to square one. Why does the PC minotaur appear to suffer from some sort of disability, even if he is a fantastically powerful minotaur barbarian?
Someone asked for more examples... Sorry. I haven't really kept up with 4e. I'm curious from a design standpoint, and I like to stay current on useful topics of geekly conversation, but since I don't actually play it, I don't have a good grasp for the PHB and MM from memory.