The PICAXE idea takes advantage of the mcu in building your own simple circuits without a lot of excess stuff.
Bingo. Many times a great, good, or even mediocre idea must wait for a confluence of technology to occur. My mediocre product is doing quite well, thank you, very recently requiring board house level fabrication and a global distribution channel.
Although the IDEA for the product had been in my head for decades, the REALITY was that I needed cheap A/D converters, a cheap LED driver and dimmer, VERY bright and small LED's, and brutally rugged voltage regulators, not to mention passive SMD components that were pure unobtainium even 10 years ago.
The Picaxe fulfilled all requirements save the LED's, regulator, and passives, which were covered with new technology. I still play "catch-up" with the LED's on an almost weekly basis. In short, the Picaxe made possible an affordable device, with easily modified code, to enable the production of a product that would otherwise not be economically viable.
In the mid 1960's my dad (an avid photographer), told me he wanted a movie camera that would "instantly display what I just filmed". He had met Ed Land, and had been told in college that the zoom lens was not "realistically possible". He lived long enough to see the confluence of technology, when I showed him my iPhone with the instant playback of the video I had just recorded of us. He actually said, "I've lived too long. I'm speechless".