My other half owns two of the 645 models in the series. Based on her recommendation my brother grabed one too. The 67/69 models are slightly different, but the principle is the same - sell a great lens at a great price, and throw in the rest of the camera for free.
By not providing interchangable lenses, and NOT making it an SLR you get something that's cheap, light, fun and takes great pictures. Individually they're not a "system", but for the price you just grab one of each! Don't change back/lens - change camera...
There's nothing else close to these things. And they're discontinuted! I've seen the 69 go for more than list on ebay since they've stopped selling them. Robert White's final price on the 69 was about £700, but they regularly sell for £800+!!!