Probably not; It's just that floating point on x86 without SSE is ridiculously awkward, and it's becoming hard to find platforms with no SSE2, so no sense in making an effort to support the x87 or SSE1 instruction sets.
Unfortunately enough people have older CPUs that we still have to support x87 code generation; its just not used in the binary packages, you have to build the source to get it.
Factor uses ahead of time compilation. When you load a source file at the REPL, all definitions in it are compiled immediately, and compiled code is saved in the image. So when you download a pre-built binary package, all the code has already been compiled so auto-detection is not an option.
There are pros and cons to both compiling at load time or run time; one of the disadvantages of the former is less flexibility when it comes to using CPU-specific features.
