Eben Upton: An educational life of Pi (The H)

Given that the Pi folks are explicitly looking back at the early microcomputer era (the C-64 in particular) as a guideline, the fact that the Raspberry Pi looks very much like that means they succeed :-)

I think there's also a lot of value in having a computer that can easily interface with hardware devices rather than just a microcontroller.

Doing simple things is simple on both devices, but then when you want to start doing UI and network type things, having a complete OS and related toolsets available is much better than having to try and rebuild the base functionality on a microcontroller.

Now, if you need thousands of devices, then the cost difference becomes a driving factor, but for one-off projects, learning, and experimentation, going the full computer route is a good approach.