Yes I would. Requiring a character set outside of ASCII is what I'd call a high-risk design decision, that could easily become a misfeature of a language. Windows "smart quotes" are bad enough and that's not even a programming language. This is why people invented J as an alternative to APL.
Most systems support UTF-8, so most of the problems have been solved by now. There's still a lot of scope for malicious or very surprising unicode; invisible characters or modifiers, font problems, RTL/LTR, characters which have different code points but cannot necessarily be visually distinguished ("ı = 1" etc), good old Zalgo, and so on.
