That device will last for three and a half hours on a 700maH battery. The devices here will last for months, if not years, on a single coin cell. Something like a wireless moisture sensor so you can more efficiently water your garden doesn't need 8 megs of ram. In such a case, why have waste all that power on parts of the chip that are never going to be used? There are a lot of areas where a small chip can do the job just as well, if not better, than a much larger chip using a more conventional OS.