Re the dumb-as-post Kobold:
See my posts not too far upthread.
Saw them.
I've seen (as player) and done (as DM) similar things many a time when it comes to Kobolds and Goblins and Orcs and the like, mostly due to bad luck on a quick random determination of what degree of intellect the party's dealing with if they take a prisoner or charm something and try to talk to it. Sometimes they get a genius among its people. Other times they get something only slightly smarter than my shoe. Most of the time it's somewhere in between.
That said, I should probably point out that I've always seen the bell curve for Kobold intelligence as being about 2-12 - 1e assigns them "Average (low)" in the MM but I'm not that nice to them. They're smart in combat or hunting situations but not much else; literacy, for example, is beyond them.
Which means that while getting stuck with an idiot Kobold is unfortunate, it's not a game-ender.
Now if over time you capture a bunch of Kobolds and every one of them turns out to be an idiot then - unless the DM's setting specifically calls out Kobolds as being stupid - you've got a very valid point. But a sample size of one just isn't enough to draw any conclusions from.
Disclaimer: obviously, I wasn't there and as such don't know the table dynamics, body language, expressions used, etc. at the time. All I can go by is the words on my screen.
Re: the quest-that-wasn't:
My objection is not that it's unrealistic. My objection is that it's bad RPGing.
As I've posted already, the GM had presented a single way for us to approach the game: by taking the "quest" from his NPC questgiver. And then he had decided - unilaterally, in advance - that by doing this thing that we were obliged (as players) to do to play the game at all, we would be subverting our own goals and making ourselves into idiots. What were we, as players, there for? To be "actors" in the GM's script?
You did the quest (because that's the only option you had), came back, and the quest turned out to be a trick. Will that do as a sum-up?
If yes, consider this: sure your PCs got hosed by the quest-giver but it's still nearly inevitable that in process of doing said quest those PCs would have become:
--- more experienced (and-or higher level) mechanically
--- more experienced in-character through learning how to function as field adventurers
--- more developed in personality (and on a meta-level, more familiar to their players)
--- a better team through learning who could and couldn't do what, both in and out of combat
--- wealthier
How are any of these things bad? How do any of these things not lead to a continuation of the party, and thus the game?
I'm also assuming the actual moments of play during the quest adventure were enjoyable enough to keep you coming back for more.
Given all this, it's perhaps not a good look if you're canning the game just because your PC got duped. Role-playing isn't all sweetness and light, after all.
