If I could take a piece of chicken out of the freezer, put it in the microwave and hit 'defrost' or 'cook' without having to look at the little sticker in the door that tells me which program I need, and without having to enter the weight, then the UI would be much improved.

A decent display and rotary dial could handle the first requirement. Turn the dial until it displays 'Chicken'. Then if the microwave had a built in scale, the second requirement could be met. Press the defrost button.