In addition to the 'cheap hardware for those that buy it as _only_ platform, not gadget no 17' reason that others provided:
I think for real progress (in a language/as a programmer) you need a goal. A project.
The Pi is even hyped and interesting among people that already have their other 16 gadgets lying around and a couple VPS on top: It's so small and so inexpensive, that you can get really creative. Never learned to solder? Doesn't matter that much if the (capable) main part of your pet project costs about as much as two dozen Cheeseburgers from McDonalds.
I think for real progress (in a language/as a programmer) you need a goal. A project.
The Pi is even hyped and interesting among people that already have their other 16 gadgets lying around and a couple VPS on top: It's so small and so inexpensive, that you can get really creative. Never learned to solder? Doesn't matter that much if the (capable) main part of your pet project costs about as much as two dozen Cheeseburgers from McDonalds.