A lot of recipes/cooking styles were based on poverty. Meatballs? A few scraps of meat and stale bread. Those fancy french sauces? Needed to mask the rancid meat. Woks? For cooking with a minimum amount of fuel. And so on and so on. Would you say they couldn't cook anything good, either?
Because much of people's preference for certain types of food are acquired and not necessary (or even beneficial). During times of poverty, there are often pressures to change preferences, leading to a much higher rate of innovation. (Special case of general mechanism in creative destruction / evolution)
Once a preference is established, it can stay for a long time because there's a physiological tendency to like food you've eaten (without ill effects) before. There are few social forces strong enough to override that.
Not at all. A lot of my favorite foods are peasant foods especially French and Italian) none of which can be made in a rice cooker. They're often quite difficult to make, they just tend to use what are (or at least long ago were) the cheaper parts of the animal.
