Arguably, that's the whole of politics: why should I give you something if you don't give me something?
The people involved are, generally, not deep thinkers, aren't aren't thinking much beyond their direct short-term advantage. The system selects against that.
No, the system selects for people who are brilliant for using it to maximize their own individual benefit. Never take the bait that these people are in anyway stupid.
Yes, check the reply for the comment above yours for an example where you'd think everyone would unite but still needed pork.
It's even worse if you're a Republican. If a bill comes up for one specific item that would increase government spending but not in your state what are you going to tell local Republican voters?
