I wish the post had gone deeper trying to answer the question. I'm not sure what the answer is, but I think several factors contributed:<p>1. Microwaves originally had analog dials. The first digital UIs were seen on fancier, high-end appliances. This made them a bit of a status symbol. Eventually, tech costs came down and everyone imitated the high-end UI.<p>2. Almost nobody grows up wanting to design appliance UIs. They're considered boring.<p>3. Removing features is <i>hard</i>. If you remove a feature used by 1% of your customers, and you have 10,000 customers, that's 100 angry people. They'll be much more vocal than the slightly happier 9900.<p>Amusingly, the cheapest microwaves are often the ones with the best interfaces. I spent $80 on something like this[1] years ago, and I like it more than any fancy microwave. This includes the model touted by the author. Having only one knob (time) is too minimalist. I hardly ever touch the power knob, but it's occasionally necessary.<p>1. <a href="http://image.haier.com/us/products/kitchen/microwaves/W020131114629227085989.png" rel="nofollow">http://image.haier.com/us/products/kitchen/microwaves/W02013...</a>