The coffee maker is literally cooking the ground coffee, which could not be drunk unless it were boiled, as opposed to instant coffee, which could be even mixed with cold water (however yucky that thought) and be edible, or even mixed into another food item such as chocolate pudding and eaten. Ground coffee is still undrinkable in its present state until it is boiled with water. Plus, the coffee maker has a filter, so maybe there is a borer issue also. There is no congruence between a light timer and a coffee timer. We are permitted to have lights on Shabbos. Fresh-cooked food or drink, we are not. I also learned our keilim do not have to rest on Shabbos, or we would never be able to have a refrigerator, heat, or A/C on. So the timer is not an issue for a light.
