[plt-scheme] Is UNICODE in the code taboo?

Hi folks,

Though MzScheme supports UNICODE and DrScheme makes it easy to insert
symbols, for example type:

1. \rightarrow
2. M:\

to get a right arrow, I am guessing that it is sort of a taboo to
include UNICODE symbols in the code.

Is it true? If so, why?

I am guessing one reason against it is every non-UNICODE-friendly tool
folks might use:

Firefox for code listing (not sure beyond code listing)
enscript
Emacs

Best wishes,

Grant