We're talking about style at that point. If someone is using those fonts to pass text off as being in a different language, as in the example you mention, then

We're talking about style at that point. If someone is using those fonts to pass text off as being in a different language, as in the example you mention, then sure, that's egregious. If, however, the font is use to render some text in the style of another language, then I don't see a problem with it. We've done the same with Greek, Russian, Japanese, and many other languages that have a distinctive script. Sometimes it's tacky, but I wouldn't call it insulting.