Originally Posted by max-a-mill
word!
you can also do achieve almost this level of simplicity much less masochistically if your so inclined by making a regular old singlespeed with only one glorious gear, but the ability to coast.
One speed is no good for distance commuters. Sure, you might be riding 70gi 90% of the time, but what about if you have a strong headwind? If your one way commute takes an hour and you get a 10mph headwind with 15-20mph gusts (fairly common), you won't have much fun if you're stuck in 70gi. Boost that wind to 20+mph with gusts over 30 (uncommon, but it happens now and then) and the ride is outright torture. Conversely, you might want 100gi if you can pick up a strong tailwind or just want to sprint.
If you're paranoid about reliability on shifters, just switch to bar end or downtube. Even if the cable breaks (your fault for not noticing it was about to go), you can always break the chain, take the derailleur out of the picture, and set it on your favorite gear so you can ride in at normal speed.