For the same reason I don't use Ada or Eiffel when I already know C++ and Java. The marginal cost of learning a new language (to the point where you could write useful programs in the style of that language) similar to one you already know is still large but the marginal benefit is very small.
I already know Common Lisp, Smalltalk, and Forth, which are all listed as influences of REBOL.
However, if I could, I'd gladly go back in time and replace some of the shitty languages I know (See ya PHP and Python) with REBOL.
If I could make some languages unimportant then I'd have even more slots (cya JavaScript, C, C++, Java), but I don't want to forget those cause I wouldn't be able to have a job if I did.
Also cool is that REBOL was made by the guy who wrote the Amiga kernel.
The UNIX hate is strong in REBOL so it is very appealing.
Name:
Anonymous2013-12-13 7:55
REBOL is written in highly portable ANSI C. It's about 500K uncompressed and is available on almost any platform. Think of all the shit you need to deal with when you just want to create a simple graphical application.
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Anonymous2013-12-13 8:09
MY ANUS
Why are you not using it yet, /prog/?
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Anonymous2013-12-13 8:10
I am thy lord thy Sussman, and you shall have no other Lisp's before mine.