This is the latest in a very honourable tradition. My first encounter with it was with Martin Richards's BCPL system in 1972. The compiler generated a hypothetical ISA called OCODE, from which backends generated pretty good native code for Titan-2 and System/360, among others. One of those backends generated INTCODE, which was an extremely reduced ISA, for which an interpreter could be easily written (I wrote one in Fortran). Richards also provided the BCPL compiler and runtime library in INTCODE, so you could quickly have BCPL running interpretively. Then you could use this interpretive version to bootstrap a native-code backend implementation. Put this all together, and you now have a very easy compiler port.

Wirth's Pascal-P compiler of 1974(?) used the same idea, also in aid of a highly portable compiler. I have never been able to find out whether this was an independent invention, or whether Wirth was influenced by Richards's work.

Of course, the JVM and CLR are descendents of this, but they build a very complex structure on the basic idea. Writing an implementation of one of these virtual machines is not for the faint of heart.

So I think Bedrock can be very useful as a compiler target, if nothing else. However, I must agree with some of the other commenters that the 64KiB address space makes it very much of a niche tool. Come up with a 32-bit variant that's not much more complicated, and I think you have a winner.