Toasters are no longer simple mechanical devices for a reason. If an "appliance" concept really worked, all you'd need is a 555 timer chip and a variable resistor. There hasn't been a toaster that simple in almost 2 decades! Why? Because even the simplest task the human mind can possibly imagine, the most uniform and consistent task a human can imagine, still has too much variability and uncertainty in it.

The "appliance" market in domestic products is DEAD. We don't have single-purpose kiosks that look one thing up, we don't use PDAs, I don't even remember the last time I saw a shop selling single-function clockwork alarm clocks. I think it was some time in the early 70s. Appliances are a failure. People WANT general purpose tools, not over-specialized ones, because you can make the tool work the way YOU work, you don't have to work the way the tool does.