[quote=Asura]
Part of me thinks taking over a land with a disgruntled and rebellious population might not be worth the resources.
[/quote]

Give them bread and circuses, and everything they're demanding. Suddenly, you have a loyal population.

Or maybe they revolt against you the moment you give them what they want. That's why you just vassalize them.
[s]Also, you get less Infamy points[/s]