All of these are examples of "shallow" or puzzle games. That's not to say that they're bad games, but it's simply not in the same market as DS games.
> I now I've sat there and played Angry Birds for an hour.
And that's an outlier. I was a kid of the Pokemon generation. I'd sit and play those games (and similar) all night, only stopping to do homework.
For a good example of what the DS market is, I'll look at the top games under "DS" on Gamefaqs. This isn't a perfect representation (represents activity on the site vs sales), but it'll do. 1 to 3 are all Pokemon. 4 is a Kingdom Hearts game, a series known for it's story more than anything. 5th is Golden Sun: Dark Dawn, a traditional RPG. 6th is more Pokemon. 7th is Dragon Quest IX, another installment in the classic RPG series. I can't speak for the rest of the list because I don't know the games mentioned, but by now you should have noticed a trend: RPGs and story. These are games that (as a kid) I'd play for an hour at a minimum. You can easily get 20 or 30 hours out of these and that's before replay value (which absolutely ridiculous when you're talking about Pokemon).
That $30 isn't just something to keep you distracted on the bus; it's something you'll put some time into playing. I don't mean to sound rude, but it seems like something you just aren't getting as a "non-gamer". I don't mean that in a bad way, but to me there's a massive difference between Angry Birds: February Edition! and the next installment in an RPG series I know and love. One will give me quick diversion while I wait in line, but the other one will offer me hours upon hours of entertainment and story.
Edit: Apologies for the tone of this post. I love Angry Birds and similar for what they are, but I have a pet peeve about people conflating casual/social games with video games as a whole.
