I recently visited a website which back end could not parse non-ascii character for credit card information. Here I am, willing to spend perfectly good money, and the stone age website only want money from people whose name is made from a-z.

Treating text and ascii as the same thing is bad. Its bad for technological reasons, its bad for economical reasons, and its just plain bad. If you think it "runs", it simply because all those customer who get "invalid character" error has gone over to a competitor and didn't bother to tell you.