The problem in GC vs RC and decisions taken by companies, is that many times the decisions are political and not technical.
The outcome of Singularity and Midori is a proof of it, in spite of the outcomes prooven by their research, the projects were killed by management.
At least they allowed some of the tech to be repurposed for .NET Native.
It may be the embedded world has very advanced GCs that would perform well on modern mobile platforms, and just nobody has gotten around to integrating them yet. I don't know! But embedded devices with predictable workload that you can model and test are quite a different beast from a general-purpose computer, so that remains to be proven.